Management of metastatic glomus jugulare tumors

METASTATIC GLOMUS JUGULARE TUMORS (JUGULAR PARAGANGLIOMAS) ARE VERY UNCOMMON: consequently, no single report has been able to accurately describe their biologic or clinical behavior, and there are no established guidelines on caring for patients with these tumors. Identification of metastatic paraganglioma can be difficult because these tumors are known to occur synchronously, many other tumor types appear histologically similar to paragangliomas, and histologically the metastasis may not resemble the primary tumor. Immunohistochemistry, using neuroendocrine markers, and electron microscopy are the two most useful techniques available to identify definitely paragangliomas. A few studies have shown differences in the immunohistochemical staining patterns between benign and metastatic paragangliomas. We reviewed the literature and include two additional cases of metastatic glomus jugulare tumors in this article. We discuss the clinical management of these patients, the importance and usefulness of immunohistochemistry in characterizing these tumors, and their clinical outcomes.

p16INK4a expression in actinic keratosis and Bowen's disease

BACKGROUND

Progression of cutaneous squamous neoplasms from actinic keratosis (AK) to Bowen's disease (BD; squamous cell carcinoma in situ) has important implications for clinical management and treatment, thus requiring accurate diagnosis. p16INK4a is a cell cycle regulatory tumour suppressor protein that negatively regulates D-type cyclins in the G1 cell cycle phase via intimate interplay with the retinoblastoma gene. Expression of a paraffin-reactive p16INK4a marker has recently been shown to increase in cervical squamous neoplasms as lesions progress from low-grade dysplasia to squamous cell carcinoma in situ. p16INK4a expression in the progression of squamous cutaneous neoplasia, however, has not been evaluated.

OBJECTIVES

To evaluate p16INK4a expression in the progression of squamous cutaneous neoplasia.

METHODS

Biopsies of 203 squamous cutaneous neoplasms with unequivocal features of AK (n = 87) and BD (n = 116) as well as a benign squamous control group (verruca vulgaris: n = 10; seborrhoeic keratosis: n = 11; scar tissue: n = 8) obtained between January and December 2001 at Henry Ford Hospital (Detroit, MI, U.S.A.) were immunostained for p16INK4a (Dako; clone E6H4; dilution 1 : 50) using large core (1.5 mm) tissue microarray analysis. Nuclear/cytoplasmic immunoreactivity in > 10% of neoplastic cells was considered positive.

RESULTS

Of 203 cases, 166 (81.8%) were interpretable (AK 59; BD 107). Mean patient age was 71.0 years (range 33-93); 57% were male. Sites of involvement were: head and extremities 75.9%, trunk/buttocks 21.7%, genital region 2.4%. p16INK4a immunostaining was positive in 90 of 107 (84.1%) BD cases, four of 59 (6.8%) AK cases and none of 29 benign squamous controls. The sensitivity and specificity of p16INK4a for a diagnosis of BD (vs. benign squamous controls/AK) was 84.1% and 95.5%, respectively (P < 0.0001, Fisher's exact test, two-sided).

CONCLUSIONS

p16INK4a is a sensitive and specific marker for distinguishing BD from AK/benign squamous cutaneous lesions and may be helpful as an adjunct to histomorphology in the diagnosis and appropriate clinical management of these lesions.

HRPT2, encoding parafibromin, is mutated in hyperparathyroidism-jaw tumor syndrome

We report here the identification of a gene associated with the hyperparathyroidism-jaw tumor (HPT-JT) syndrome. A single locus associated with HPT-JT (HRPT2) was previously mapped to chromosomal region 1q25-q32. We refined this region to a critical interval of 12 cM by genotyping in 26 affected kindreds. Using a positional candidate approach, we identified thirteen different heterozygous, germline, inactivating mutations in a single gene in fourteen families with HPT-JT. The proposed role of HRPT2 as a tumor suppressor was supported by mutation screening in 48 parathyroid adenomas with cystic features, which identified three somatic inactivating mutations, all located in exon 1. None of these mutations were detected in normal controls, and all were predicted to cause deficient or impaired protein function. HRPT2 is a ubiquitously expressed, evolutionarily conserved gene encoding a predicted protein of 531 amino acids, for which we propose the name parafibromin. Our findings suggest that HRPT2 is a tumor-suppressor gene, the inactivation of which is directly involved in predisposition to HPT-JT and in development of some sporadic parathyroid tumors.

Cytokeratin immunostaining patterns of benign, reactive lymph nodes: applications for the evaluation of sentinel lymph node specimen

The use and interpretation of cytokeratin (CK) immunostains of sentinel lymph node specimens for breast carcinoma remain controversial. Variable immunoreactivity with anti-CK antibodies and CK-positive interstitial reticulum cells may complicate interpretation. The authors examined a series of reactive lymph nodes selected from patients without a history of malignancy. To demonstrate potential diagnostic pitfalls, three different CK antibody combinations were studied to characterize the immunostaining patterns. Formalin-fixed sections of lymph nodes were immunostained with a labeled streptavidin-biotin method using a DAKO autostainer. The anti-CK antibody preparations evaluated were AE1/AE3, CAM 5.2, and an in-house-prepared CK cocktail composed of 7 antibodies. The authors observed that up to 10% of cells in benign, reactive lymph nodes may be immunoreactive with anti-CK antibodies. AE1/AE3 stained 2 of 20 cases with rare immunoreactive reticulum cells, whereas CAM 5.2 and the CK cocktail immunostained cells in 85% of cases with reticulum cells in sinuses and the paracortex. Rare positive to 2+ cells were present in a similar distribution with these two antibodies. Careful interpretation of CK immunostaining of sentinel lymph node biopsies is essential, as is awareness of the presence of CK-positive native reticulum cells, to avoid confusion with single cells of metastatic carcinoma.

Renal angiomyolipoma: further immunophenotypic characterization of an expanding morphologic spectrum

BACKGROUND

Renal angiomyolipoma is a benign tumor histologically characterized by proliferation of spindle cells, epithelioid cells, and adipocytic cells in concert with many thick-walled blood vessels. To add further diagnostic confusion, an epithelioid cell-predominant variant of renal angiomyolipoma has recently been described. HMB-45 immunoreactivity correlates with ultrastructural striated organelles that closely resemble premelanosomes, although no evidence of melanogenesis has been documented in this tumor.

OBJECTIVE

To further characterize the immunophenotypic and ultrastructural profile of renal angiomyolipoma based on phenotypic cell type (epithelioid, spindle, and adipocytic cell).

DESIGN

Formalin-fixed, paraffin-embedded tissues from 27 renal angiomyolipomas and 8 renal cell carcinomas were immunostained with monoclonal antibodies to the melanoma-associated antigens HMB-45, HMB-50, NKI/C3 (CD63), and tyrosinase; the smooth muscle-related antigens calponin and muscle-specific actin (HHF-35); S100; and cytokeratin (CK). All renal angiomyolipomas were also immunostained with a polyclonal antibody to renin. Ultrastructural examination was performed on 9 selected cases.

RESULTS

All renal angiomyolipomas stained positive for HMB-45, HMB-50, NKI/C3, muscle-specific actin (HHF-35), and calponin. Overall, HMB-45, HMB-50, and NKI/C3 preferentially stained the epithelioid cells. Tyrosinase staining was present in 50% of the renal angiomyolipomas with adequate tissue for staining (12 of 24 cases); positive staining and intensity paralleled HMB-45, HMB-50, and NKI/C3. Muscle-specific actin (HHF-35) and calponin preferentially stained the spindle cells. The adipocytic cells stained positive for both melanoma-associated antigens and smooth muscle antigens. Epithelioid cells, spindle cells, and adipocytic cells were CK, S100, and renin negative. Ultrastructural findings paralleled immunohistochemical staining patterns. Premelanosome-like organelles and electron dense granules were more readily detected in the epithelioid cells within the tumor, whereas ultrastructural characteristics of smooth muscle cells were more easily found in the spindle cells. All renal cell carcinomas stained positive for CK, NKI/C3 staining was variable, and all were negative for HMB-45, HMB-50, smooth muscle actin (HHF-35), and calponin.

CONCLUSION

In renal angiomyolipoma, the epithelioid and spindle cells have preferential staining patterns for melanoma-associated antigens versus smooth muscle antigens, respectively. Positivity in renal angiomyolipoma for HMB-50, NKI/C3, and tyrosinase, in addition to HMB-45, provides evidence for the presence of different melanoma-associated gene products. Immunophenotypic overlap of the 3 histologically distinct renal angiomyolipoma cell populations suggests a common cell line, supporting a unitarian concept for renal angiomyolipoma. Ultrastructural characteristics of the 3 renal angiomyolipoma cell phenotypes parallel the immunophenotype, giving further support to a common cell line. Our study lends further credence to the perivascular epithelioid cell concept as proposed by Bonetti and colleagues.

Renal angiomyolipoma: further immunophenotypic characterization of an expanding morphologic spectrum

BACKGROUND

Renal angiomyolipoma is a benign tumor histologically characterized by proliferation of spindle cells, epithelioid cells, and adipocytic cells in concert with many thick-walled blood vessels. To add further diagnostic confusion, an epithelioid cell-predominant variant of renal angiomyolipoma has recently been described. HMB-45 immunoreactivity correlates with ultrastructural striated organelles that closely resemble premelanosomes, although no evidence of melanogenesis has been documented in this tumor.

OBJECTIVE

To further characterize the immunophenotypic and ultrastructural profile of renal angiomyolipoma based on phenotypic cell type (epithelioid, spindle, and adipocytic cell).

DESIGN

Formalin-fixed, paraffin-embedded tissues from 27 renal angiomyolipomas and 8 renal cell carcinomas were immunostained with monoclonal antibodies to the melanoma-associated antigens HMB-45, HMB-50, NKI/C3 (CD63), and tyrosinase; the smooth muscle-related antigens calponin and muscle-specific actin (HHF-35); S100; and cytokeratin (CK). All renal angiomyolipomas were also immunostained with a polyclonal antibody to renin. Ultrastructural examination was performed on 9 selected cases.

RESULTS

All renal angiomyolipomas stained positive for HMB-45, HMB-50, NKI/C3, muscle-specific actin (HHF-35), and calponin. Overall, HMB-45, HMB-50, and NKI/C3 preferentially stained the epithelioid cells. Tyrosinase staining was present in 50% of the renal angiomyolipomas with adequate tissue for staining (12 of 24 cases); positive staining and intensity paralleled HMB-45, HMB-50, and NKI/C3. Muscle-specific actin (HHF-35) and calponin preferentially stained the spindle cells. The adipocytic cells stained positive for both melanoma-associated antigens and smooth muscle antigens. Epithelioid cells, spindle cells, and adipocytic cells were CK, S100, and renin negative. Ultrastructural findings paralleled immunohistochemical staining patterns. Premelanosome-like organelles and electron dense granules were more readily detected in the epithelioid cells within the tumor, whereas ultrastructural characteristics of smooth muscle cells were more easily found in the spindle cells. All renal cell carcinomas stained positive for CK, NKI/C3 staining was variable, and all were negative for HMB-45, HMB-50, smooth muscle actin (HHF-35), and calponin.

CONCLUSION

In renal angiomyolipoma, the epithelioid and spindle cells have preferential staining patterns for melanoma-associated antigens versus smooth muscle antigens, respectively. Positivity in renal angiomyolipoma for HMB-50, NKI/C3, and tyrosinase, in addition to HMB-45, provides evidence for the presence of different melanoma-associated gene products. Immunophenotypic overlap of the 3 histologically distinct renal angiomyolipoma cell populations suggests a common cell line, supporting a unitarian concept for renal angiomyolipoma. Ultrastructural characteristics of the 3 renal angiomyolipoma cell phenotypes parallel the immunophenotype, giving further support to a common cell line. Our study lends further credence to the perivascular epithelioid cell concept as proposed by Bonetti and colleagues.

Renal angiomyolipoma: further immunophenotypic characterization of an expanding morphologic spectrum

BACKGROUND

Renal angiomyolipoma is a benign tumor histologically characterized by proliferation of spindle cells, epithelioid cells, and adipocytic cells in concert with many thick-walled blood vessels. To add further diagnostic confusion, an epithelioid cell-predominant variant of renal angiomyolipoma has recently been described. HMB-45 immunoreactivity correlates with ultrastructural striated organelles that closely resemble premelanosomes, although no evidence of melanogenesis has been documented in this tumor.

OBJECTIVE

To further characterize the immunophenotypic and ultrastructural profile of renal angiomyolipoma based on phenotypic cell type (epithelioid, spindle, and adipocytic cell).

DESIGN

Formalin-fixed, paraffin-embedded tissues from 27 renal angiomyolipomas and 8 renal cell carcinomas were immunostained with monoclonal antibodies to the melanoma-associated antigens HMB-45, HMB-50, NKI/C3 (CD63), and tyrosinase; the smooth muscle-related antigens calponin and muscle-specific actin (HHF-35); S100; and cytokeratin (CK). All renal angiomyolipomas were also immunostained with a polyclonal antibody to renin. Ultrastructural examination was performed on 9 selected cases.

RESULTS

All renal angiomyolipomas stained positive for HMB-45, HMB-50, NKI/C3, muscle-specific actin (HHF-35), and calponin. Overall, HMB-45, HMB-50, and NKI/C3 preferentially stained the epithelioid cells. Tyrosinase staining was present in 50% of the renal angiomyolipomas with adequate tissue for staining (12 of 24 cases); positive staining and intensity paralleled HMB-45, HMB-50, and NKI/C3. Muscle-specific actin (HHF-35) and calponin preferentially stained the spindle cells. The adipocytic cells stained positive for both melanoma-associated antigens and smooth muscle antigens. Epithelioid cells, spindle cells, and adipocytic cells were CK, S100, and renin negative. Ultrastructural findings paralleled immunohistochemical staining patterns. Premelanosome-like organelles and electron dense granules were more readily detected in the epithelioid cells within the tumor, whereas ultrastructural characteristics of smooth muscle cells were more easily found in the spindle cells. All renal cell carcinomas stained positive for CK, NKI/C3 staining was variable, and all were negative for HMB-45, HMB-50, smooth muscle actin (HHF-35), and calponin.

CONCLUSION

In renal angiomyolipoma, the epithelioid and spindle cells have preferential staining patterns for melanoma-associated antigens versus smooth muscle antigens, respectively. Positivity in renal angiomyolipoma for HMB-50, NKI/C3, and tyrosinase, in addition to HMB-45, provides evidence for the presence of different melanoma-associated gene products. Immunophenotypic overlap of the 3 histologically distinct renal angiomyolipoma cell populations suggests a common cell line, supporting a unitarian concept for renal angiomyolipoma. Ultrastructural characteristics of the 3 renal angiomyolipoma cell phenotypes parallel the immunophenotype, giving further support to a common cell line. Our study lends further credence to the perivascular epithelioid cell concept as proposed by Bonetti and colleagues.

Surgical pathology-based outcomes assessment of breast cancer early diagnosis: a College of American Pathologists Q-Probes study in 199 institutions

OBJECTIVE

To develop breast cancer outcomes data relating pathologic tumor variables at diagnosis with clinical method of detection.

DESIGN

Anatomic pathologists assessed 30 consecutive breast cancers at each institution, resulting in an aggregate database of 4232 breast cancers.

SETTING

Hospital-based laboratories from the United States (98%), Canada, Australia, and Belgium.

PARTICIPANTS

One hundred ninety-nine laboratories in the 1999 College of American Pathologists Q-Probes voluntary quality improvement program.

MAIN OUTCOME MEASURES

Pathologic variables indicative of favorable outcomes included percentage of carcinomas detected at the in situ stage, tumors < or = 1 cm in diameter, and invasive cancers with lymph nodes negative for metastases.

RESULTS

All outcomes measures, including percent in situ carcinomas (26.9% vs 13.8%), tumor size < or = 1 cm (57.8% vs 36.5%), and lymph node-negative status (77.8% vs 64%), were more favorable when tumors were detected by screening mammography (P <.001) compared to all other detection methods.

CONCLUSIONS

This study demonstrates an opportunity for pathologists to develop outcomes information of interest to health care organizations, providers, patients, and payers by integrating routine oncologic surgical pathology and clinical breast cancer detection data. Such readily obtained interim outcomes data trended and benchmarked over time can demonstrate the relative clinical efficacy of preventive breast care provided by health care systems long before mortality data are available.

Two-color, cytokeratin-labeled dna flow cytometric analysis of 332 breast cancers: lack of prognostic value with 12-year follow-up

CONTEXT

DNA flow cytometry of breast cancer is a proposed tumor marker of prognostic significance that is of controversial clinical utility because of lack of standardization and confirmatory studies.

OBJECTIVE

To evaluate the prognostic significance of the more informative technique of multiparametric 2-color DNA flow cytometry as recommended by the 1992 DNA Cytometry Consensus Conference.

DESIGN

Three hundred thirty-two breast carcinomas with 7 to 12 years of follow-up were prospectively analyzed as fresh tumors that were mechanically dissociated into whole cell suspensions. These suspensions were dual fluorescence-labeled with propidium iodide (DNA) and antibodies to cytokeratin (epithelium) and leukocyte common antigen (internal leukocyte control) for gated analysis of subpopulations. Multicycle software with histogram-dependent algorithms employing background, aggregate, and debris correction were used in DNA and cell-cycle quantitation. Data were analyzed according to the DNA Flow Cytometry Consensus Conference recommendations.

RESULTS

DNA ploidy and proliferation stratified into 3 categories were not predictive of overall or disease-free survival. Sixty-five percent of tumors were nondiploid, and 35.4% were diploid. Two hundred six tumors were able to be evaluated for synthesis-phase fraction (SPF) analysis, with 74 of 206 cases in the low range (<13.4%), 36.4% in the intermediate range (>13.5 to <25.4%), and 27.6% in the high SPF (>25.5%) category. Aneuploid tumors tended to have a higher SPF. Univariate survival analysis showed prognostic significance of the following: tumor size, stage, TNM components, vascular invasion, nuclear grade, and histologic grade. Only T classification, presence of positive axillary lymph nodes, and distant metastases were significant independent predictors of survival in multivariate Cox regression models. Age and hormone receptor status showed no prognostic significance. Synthesis-phase fraction was significantly correlated with tumor size, stage, T classification, nuclear and histologic grade, presence of estrogen or progesterone receptors, and axillary lymph node status. None of the histologic parameters showed any significant association with DNA aneuploidy, except for high nuclear and histologic grade and the absence of estrogen receptors.

CONCLUSIONS

Despite the use of state-of-the-art processing and flow cytometry analytic techniques, DNA ploidy and proliferation measurements were not predictive of survival in any stage of breast cancer. However, select histopathologic parameters and TNM stage were significant predictors of survival in univariate and multivariate analyses. We conclude that DNA ploidy and proliferation measurements do not provide significant prognostic information for clinicians to integrate into therapeutic decision making for patients with breast cancer.

Molecular approaches to identification of tissue contamination in surgical pathology sections

The finding of possibly contaminant tissues or cells in surgical or cytology case material can be a challenging problem in diagnostic anatomical pathology samples. The reported rates of occurrence have ranged from 0 to 8.8% (including prospective and retrospective cases). A diagnostically dissimilar tissue fragment, whether contiguous with other tissue or among other fragments within a paraffin section, and which is not incompatible with the case tissue, often requires a rigorous investigation to confirm or deny its relevance to the case. Fluorescence in situ hybridization using dual red and green DNA probes to regions of the X and Y chromosomes, respectively, were used in one case where the potential contaminant was suspected to have originated from a male patient. The putative contaminant tissue fragment was confirmed as male, with cells having one X and one Y chromosome, unlike the other tissue fragments on the slide with two X chromosomes. In a second case, DNA polymorphisms were used to compare allelic patterns that were informative not only in proving the extraneous tissue as a contaminant, but in addition, could be used to trace the latter to its original tissue source. The molecular tools of fluorescence in situ hybridization in sex-mismatched cases and of DNA microsatellite probes that are applicable to paraffin sections can provide definitive identifiers of tissues and individual cells. They are important adjuncts to histology for the anatomical pathologist when faced with the diagnostic problems of tissue contamination encountered in routine practice.

The association of HER-2/neu amplification with breast cancer recurrence

HYPOTHESIS

Amplification of the HER-2/neu oncogene in 25% of breast cancers is associated with a shortened disease-free survival.

DESIGN

Retrospective analysis of a patient population referred to a tertiary care facility for HER-2/neu testing. The mean follow-up was 56 months.

SETTING

Large, urban, tertiary care hospital.

PATIENTS

From 1995 to 1999, a consecutive sample of 190 patients with breast cancer had tissue samples tested for overexpression of the cell surface oncoprotein by immunostaining (IM) or amplification of the HER-2/neu oncogene by fluorescence in situ hybridization or both. Forty-nine subjects were excluded because they had tissue samples tested at our institution but received their treatment elsewhere. All patients tested for HER-2/neu after diagnosis with breast cancer in 1999 (n = 47) were excluded from analysis because of short follow-up time. One patient was excluded who had in situ ductal carcinoma. The remaining 93 patients were analyzed.

RESULTS

Of 93 patients, 40 (43%) had gene amplification. Overall, patients with oncogene amplification had a shorter median disease-free interval (22 months) compared with controls (40 months) (P =.003). Analysis by the Cox regression model showed that the HER-2/neu status remained significantly associated with time to relapse even after adjusting for age and tumor grade (P =.002; adjusted relative risk, 2.4; 95% confidence interval, 1.4-4.4). No association was found between gene amplification and tumor grade (P =.98), estrogen/progesterone receptor status (P = .29 and P = .43, respectively), or lymph node status (P = .98). Seventy-two patients (77%) eventually had disease recurrence, with 18 (25%) of these recurring locally.

CONCLUSIONS

The HER-2/neu oncogene is an independent prognostic indicator of a subset of breast cancers that are at high risk of early recurrence, regardless of tumor grade, estrogen/progesterone receptor status, and lymph node status. Patients amplifying the HER-2/neu oncogene have a shorter disease-free survival than patients without the oncogene.

Ultrastructural observations on mitochondria and microvesicles in renal oncocytoma, chromophobe renal cell carcinoma, and eosinophilic variant of conventional (clear cell) renal cell carcinoma

On light microscopic examination, the morphologically overlapping features of granular eosinophilic cytoplasm in renal oncocytoma and the eosinophilic variants of chromophobe renal cell carcinoma and conventional (clear cell) renal cell carcinoma may pose difficulties in diagnosis. We investigated the ultrastructure of 5 renal oncocytomas, 7 eosinophilic variants of chromophobe renal cell carcinoma, and 5 eosinophilic variants of conventional (clear cell) renal cell carcinoma. Special attention was paid to mitochondria and microvesicles and interrelations thereof. The electron microscopic features were correlated with the light microscopic findings. All of the tumors had abundant mitochondria. Although abundant microvesicles were present in all of the chromophobe renal cell carcinomas, scant numbers of microvesicles were also sometimes present in renal oncocytomas (2 of 5) and in the eosinophilic variant of conventional (clear cell) renal cell carcinoma (1 of 5). The mitochondria in all three types of renal neoplasms studied differed in morphology, being predominantly uniform and round with predominantly lamellar cristae in renal oncocytoma, variable in shape and size with predominantly tubulocystic cristae in chromophobe renal cell carcinoma, and swollen and pleomorphic with rarefied matrix and attenuated cristae in the eosinophilic variant of conventional (clear cell) renal cell carcinoma. Variable numbers of mitochondria in all of the chromophobe renal cell carcinomas had outpouchings of the outer membranes, some of which carried parts of inner membrane within them. These outpouchings closely resembled the nearby cytoplasmic microvesicles, as did the tubulocystic cristae of the mitochondria. Some microvesicles contained homogeneous, electron-dense, finely granular matrix, similar to that seen in mitochondria. In one of seven chromophobe renal cell carcinomas, microvesicles were present in rough endoplasmic reticulum, and in two others, mitochondria were present within some vesicles. These features strongly suggest a close relationship between the microvesicles and mitochondria. Based on the role of vesicle formation in normal mitochondriogenesis, and some of our observations, we propose that defective mitochondriogenesis may be the source of microvesicles in chromophobe renal cell carcinomas.

The oncologic pathology report. Quality by design

OBJECTIVE

To review tenets of basic quality assurance and identify opportunities for quality improvement in the laboratory assessment of prognostic factors.

DESIGN

College of American Pathologists Q-Probes data obtained from hundreds of American laboratories throughout the 1990s are used to illustrate laboratory performance and practice opportunities in the preanalytic, analytic, and postanalytic phases of the total testing process.

RESULTS

A wide range of performance deficiencies are documented, most in the preanalytic and postanalytic phases, and contributed by individuals outside and not under the control of the laboratory. In the analytic phase, the effectiveness of checklists on the content and completeness of reported diagnostic and prognostic data for breast and colon cancers is proven.

CONCLUSIONS

In the preanalytic phase, marked enhancements in quality would result from improvements in (1) patient and specimen identification, (2) adherence to patient-sampling and specimen-handling requirements, and (3) communication to the laboratory of the pertinent clinical context of the individual test. Once basic analytic quality control and laboratory quality assurance issues are resolved, a focus on standardization and enhancement of preanalytic and postanalytic communications and satisfaction of clinical expectations becomes the source of improved laboratory performance.

Microvessels that predict axillary lymph node metastases in patients with breast cancer

HYPOTHESIS

The density of vasoactive endothelial growth factor receptor 3-immunostained microvessels in primary breast cancers correlates with the incidence of axillary lymph node metastasis.

DESIGN

Breast cancer microvessel clusters ("hot spots") were sequentially immunostained for factor VIII, type IV collagen, and vasoactive endothelial growth factor receptor 3. Microvessels were counted under light microscopy at a magnification of x 200. Axillary lymph nodes were evaluated for metastases by light microscopy.

SETTING

A multidisciplinary breast cancer clinic and laboratory.

PATIENTS

Sixty patients with T2 breast cancers treated by lumpectomy (or mastectomy) and axillary lymphadenectomy.

MAIN OUTCOME MEASURES

Putative lymphatic microvessel density compared with axillary metastases.

RESULTS

There were 16% (SE, 1.4%) vs 4% (SE, 0.8%) vasoactive endothelial growth factor receptor 3-immunostained microvessels (P<.001), 38% (SE, 3.9%) vs 65% (SE, 3.1%) type IV collagen-immunostained microvessels (P<.001), and 46% (SE, 4.1%) vs 31% (SE, 3.2%) unstained microvessels (P = .004) in node-positive vs node-negative patients, respectively. A fitted logistic model based on the relative percentage of putative lymphatic microvessels to blood microvessels correctly predicted that 23 (96%) of 24 patients would have a low risk and that 26 (96%) of 27 patients would have a high risk of lymph node metastases. Six (67%) of 9 patients predicted to have an intermediate risk had lymph node metastases.

CONCLUSION

The odds of a patient with breast cancer having axillary lymph node metastasis increased substantially as the proportion of putative lymphatic microvessels increased and the relative proportion of blood microvessels in angiogenic hot spots decreased (log likelihood = 14.6; chi2 = 53.4; P<.001; area under the receiver operation characteristic curve = 0.97).

Salivary gland basal cell and canalicular adenomas: immunohistochemical demonstration of myoepithelial cell participation and morphogenetic considerations

OBJECTIVE

To evaluate cellular composition of salivary gland adenomas using 3 monoclonal antibodies that recognize a smooth muscle phenotype confirmed to be sensitive for myoepithelial differentiation.

DESIGN

Immunohistochemical evaluation of 25 salivary gland basal cell and canalicular adenomas.

SETTING

Archival pathology material from the files of Henry Ford Hospital, Detroit, Mich, and the University of California at San Francisco.

RESULTS

All basal cell adenoma variants exhibit some degree of myoepithelial cell participation with periductal, epithelioid, and spindled (stromal-like) morphologic structures. Only the canalicular adenomas, even if mixed with trabecular and solid patterns, are devoid of staining with these 3 antibodies, suggesting an adenoma composed exclusively of ductal luminal cells.

CONCLUSIONS

There is an overlapping histomorphologic and common cellular composition of the basal cell adenoma variants with other recognized adenomas, such as pleomorphic adenoma and myoepithelioma. Relative differentiation toward 3 cell phenotypes (ductal luminal, basal, and myoepithelial) and the character of extracellular matrix production in varying proportions by the neoplastic myoepithelial cells distinguishes the spectrum of salivary gland adenomas identified in current classification schemes.

Monitoring anatomic pathology practice through quality assurance measures

This article describes the art and science of continuous performance measurement and applications for quality improvement in anatomic pathology. Numerous novel benchmarks derived from multi-institutional data acquired from the College of American Pathologists Q-Probes quality improvement program are illustrated as they relate to specific disciplines in anatomic pathology and aspects of the total testing cycle. Comparative data quantifying performance deficiencies and opportunities for practice improvement are also identified.

The myoepithelial immunophenotype in 135 benign and malignant salivary gland tumors other than pleomorphic adenoma

BACKGROUND

We have previously studied the immunoreactivity of 3 novel smooth muscle-specific proteins, alpha-smooth muscle actin, smooth muscle myosin heavy chains, and calponin, to assess myoepithelial differentiation in pleomorphic adenomas.

OBJECTIVE

To further expand our knowledge of myoepithelial differentiation in other benign and malignant salivary gland tumors.

DESIGN

Formalin-fixed paraffin sections of 135 salivary gland tumors with associated normal glands were stained with monoclonal antibodies using the avidin-biotin complex immunoperoxidase method and enzymatic and microwave heat-induced epitope retrieval.

RESULTS

In adenoid cystic carcinomas and epithelial-myoepithelial carcinomas, all 3 markers exclusively highlighted the myoepithelial cell components and the epithelial cells were entirely negative. No immunostaining was detected in canalicular adenomas, oncocytomas, Warthin tumors, acinic cell carcinomas, mucoepidermoid carcinomas, squamous cell carcinomas, and polymorphous low-grade adenocarcinomas. Salivary duct carcinomas and adenocarcinomas, not otherwise specified had a distinctive pattern of uniform periductal staining of reactive myofibroblastic cells, and in salivary duct carcinomas some ducts retained a peripheral immunoreactive myoepithelial cell layer.

CONCLUSION

Immunoreactivity for these 3 smooth muscle-specific proteins confirms the known neoplastic myoepithelial component of adenoid cystic carcinomas and epithelial-myoepithelial carcinomas. The consistently positive staining pattern in adenoid cystic carcinomas may be diagnostically useful in discriminating histologically similar but consistently negative polymorphous low-grade adenocarcinomas. Periductal linear staining in adenocarcinoma, not otherwise specified and salivary duct carcinomas is distinctive and appears to represent a tight cuff of myofibroblasts associated with the infiltrating glands.

Diagnostic uncertainty expressed in prostate needle biopsies. A College of American Pathologists Q-probes Study of 15,753 prostate needle biopsies in 332 institutions

OBJECTIVE

To determine the rate of diagnostic uncertainty in rendering diagnoses on prostate needle biopsies and to examine pathology practice variables that influence that rate.

DESIGN

Anatomic pathology departments participating in the College of American Pathologists Q-Probes laboratory quality improvement program retrospectively reviewed their last 50 consecutive prostate needle biopsy diagnoses. For each diagnosis, participants provided information concerning patients' prostate-specific antigen levels; number, locations, and laterality of biopsy specimens; number of tissue levels examined; performance of high-molecular-weight cytokeratin immunoperoxidase staining; and acquisition of consultations from general pathologists or experts in prostate pathology. Characteristics of pathology practices included yearly surgical and prostate needle biopsy caseloads, number of pathologists rendering biopsy diagnoses, use of standard descriptive checklists, access to patients' prostate-specific antigen and digital rectal examination results, percentages of prostate needle biopsies routinely submitted for internal consultations, and presence of departmental experts in prostate pathology.

SETTING AND PARTICIPANTS

Three hundred thirty-two public and private institutions located in the United States (n = 318), Canada (n = 6), Australia (n = 5), United Kingdom (n = 2), and Guam (n = 1).

MAIN OUTCOME MEASURE

The rate of diagnostic uncertainty in prostate needle biopsy diagnoses.

RESULTS

Participants submitted diagnoses on a total of 15 753 prostate needle biopsy cases, of which 33.4% were adenocarcinoma; 55.5% were benign; 3.9% were carcinoma in situ, prostatic intraepithelial neoplasia, or both; and 7.1% were diagnostically uncertain. The median rate of diagnostic uncertainty was 6%, ranging from 0 at the 10th percentile to 14% at the 90th percentile of all participating laboratories. Performing high-molecular-weight cytokeratin immunoperoxidase staining resolved diagnostic uncertainty in 68% of cases in which it was performed, and obtaining intradepartmental and extradepartmental consultations resolved diagnostic uncertainty in 70% to 87% of cases for which they were obtained. Knowledge of patients' prostate-specific antigen results and examining multiple biopsy cores had marginal effects on the rate of uncertainty. Thoroughness of prostate gland sampling and examination of multiple tissue block levels were not associated with the aggregate rate of diagnostic uncertainty. We found no particular pathology departmental practices or institutional demographic characteristics associated with institutional rates of diagnostic uncertainty.

CONCLUSIONS

Use of high-molecular-weight cytokeratin immunoperoxidase staining and obtaining intradepartmental and extradepartmental consultations may be effective in reducing diagnostic uncertainty in prostate biopsies.

Necessity of clinical information in surgical pathology

OBJECTIVES

To examine the frequency and nature of problems caused by inadequate clinical data provided on surgical pathology requisition forms.

DESIGN

Participants in the 1996 Q-Probes voluntary quality improvement program of the College of American Pathologists were asked to document prospectively all surgical pathology cases with inadequate information. Inadequate clinical information was defined as the pathologist's need for additional clinical information before a diagnosis could be rendered, regardless of the amount of information already present on the requisition slip. Cases that had no clinical information on a requisition slip were not counted if the lack of history did not hinder diagnosis. The study concluded when 3 months had elapsed or 40 surgical pathology cases were documented. The following data were recorded for each case: anatomic site, type of procedure, nature of disease, method of obtaining additional information, importance of obtained information, and the length of delay in the final diagnosis.

PARTICIPANTS

Three hundred forty-one laboratories, 322 of which were from the United States.

RESULTS

A total of 5594 cases (0.73%) required additional clinical information for diagnosis (10th through 90th percentile range, 3.01% to 0.08%). Institutions with greater average occupied bedsize, a greater number of cases accessioned per year, and a greater number of pathologists had a lower percentage of cases with inadequate clinical data (P <.05). Sixty-eight percent of these cases had no delay in completion of a case, 16.2% had a delay of 1 day or less, and 15.1% of cases were delayed more than 1 day. In 59.4% of cases, the additional clinical information obtained confirmed the initial diagnostic impression. In 25.1%, the information was not relevant to the pathologic diagnosis. In 6.1% there was a substantial change in the diagnosis or a revised report was issued, and in 2.2% no additional information could be obtained. Specific anatomic sites that correlated with a higher rate of changed diagnoses or revised reports in cases with inadequate information included the small bowel, the bronchus/lung, and the ovary. Resection specimens were also significantly associated with a higher rate of changed diagnoses or revised reports when additional information was obtained, as were malignant neoplasms and therapy-induced changes.

CONCLUSIONS

This study establishes an aggregate rate of cases with inadequate clinical information for diagnosis (0.73%) and documents the extent of problems caused by inadequate clinical information. The criticality of appropriate clinical information provided to the pathologist is identified for specific anatomic sites and disease processes and is reflected in changed diagnoses or revised reports.

Immunohistochemical profile of myogenin and MyoD1 does not support skeletal muscle lineage in alveolar soft part sarcoma

BACKGROUND

The histogenesis of alveolar soft part sarcoma remains elusive. Myogenic origin is favored, although conflicting data on immunohistochemical demonstration of muscle-associated markers exist. Myogenin and MyoD1, transcription factors of the myogenic determination family, have crucial roles in commitment and differentiation of mesenchymal progenitor cells to myogenic lineage and in maintenance of skeletal muscle phenotype. Their immunohistochemical detection is specific in characterization of rhabdomyosarcoma.

METHODS

Antibodies for myogenin, MyoD1, desmin, and muscle-specific actin were employed on a large series of cases (n = 19) of formalin-fixed, paraffin-embedded alveolar soft part sarcoma.

RESULTS

Minimal scattered nuclear staining was seen with myogenin. All cases had pronounced, nonspecific granular cytoplasmic immunostaining with MyoD1; nuclei were negative. All tumors were negative for desmin and muscle-specific actin. Ultrastructural study in 10 cases failed to reveal features of skeletal muscle differentiation.

CONCLUSIONS

Cytoplasmic staining with MyoD1 in alveolar soft part sarcoma may correspond to cross-reactivity with an undetermined cytoplasmic antigen. The lack of immunostaining with myogenin, MyoD1, desmin, and muscle-specific actin provides evidence against a myogenic origin for alveolar soft part sarcoma.

Autopsy result utilization: a College of American Pathologists Q-probes study of 256 laboratories

OBJECTIVES

To document the level of involvement and communication with nonpathology clinical personnel regarding autopsies and to document the destination of autopsy reports.

DESIGN

The College of American Pathologists Q-Probes format was used to collect information on 15 consecutively performed autopsies per institution or for 6 months, whichever occurred first. The following information was recorded for each autopsy: decedent's age, hospital service, length of hospital stay, whether organs were donated, who was present at autopsy, methods of communicating preliminary and final autopsy results, special techniques used to arrive at a preliminary diagnosis, activities for which the autopsy was used, and destination of final report.

PARTICIPANTS

Two hundred fifty-six laboratories collected information on 2755 autopsies.

RESULTS

The aggregate autopsy rate was 12.4% (median 8.5%). Nonpathology clinical personnel attended 35.8% of all autopsies. A clinical physician was more likely to attend an autopsy if the patient was from a surgical service. Three primary methods were used to communicate preliminary autopsy results, namely, written reports (82.5%), telephone calls (50.6%), and meetings (11.5%). The primary care physician was sent the autopsy report in 91.1% of cases. Approximately half of the autopsy cases were used in both pathology departmental and extradepartmental activities. Aggregate autopsy data were distributed in the majority of cases to various departmental chairpersons and institutional quality assurance committees.

CONCLUSIONS

This study provides a comparative multiinstitutional database for the utilization of autopsy results by clinicians and clinical departments. Although autopsy rates are low, autopsy results are routinely being used for hospital quality assurance activities and for educational purposes.

The autopsy as a performance measurement tool--diagnostic discrepancies and unresolved clinical questions: a College of American Pathologists Q-Probes study of 2479 autopsies from 248 institutions

OBJECTIVE

To develop a multi-institutional reference database for quality improvement purposes using the autopsy to define clinical diagnostic discrepancies and resolve clinical questions.

DESIGN

Using the College of American Pathologists Q-Probes format, institutions prospectively assessed a maximum of 15 consecutive autopsies each, excluding forensic cases and stillborn infants, conducted over a 6-month period. They documented answers to clinical questions provided at autopsy and classified unexpected disease diagnoses according to a standardized system.

SETTING AND PARTICIPANTS

Hospital-based autopsies performed at 248 institutions participating in the 1993 College of American Pathologists Q-Probes Quality Improvement Program.

MAIN OUTCOME MEASURES

Percentages of clinical questions resolved by the autopsy and percentage of autopsies with unexpected findings of graded clinical impact.

RESULTS

In the aggregate database of 6427 questions from 2479 autopsies, overall 93.0% were answered by the autopsy. The 3 most common question categories were (1) identify pathology to account for clinical signs or symptoms (28.0%); (2) establish the cause of death (21.0%); and (3) confirm a clinical diagnosis (19.0%). At least one major unexpected disease finding that contributed to the patient's death was discovered in 39.7% of the total number of autopsies. There were no differences in the percentages of autopsies with these major unexpected findings when the data were stratified by institutional demographics or decedent characteristics.

CONCLUSION

This multi-institutional study underscores the clinical relevance of postmortem examination in current medical practice by consistently providing answers to unresolved clinical questions and frequently revealing major unexpected findings that contributed to the patient's death. It is our strong belief that this postmortem-derived clinicopathologic information is a key indicator of effectiveness of care. Integration of this information into institutional quality improvement programs will improve system processes and clinician performance.

Chromosomal aberrations identified in culture of squamous carcinomas are confirmed by fluorescence in situ hybridisation

AIMS

Chromosomal aberrations in tumour cells are often not discernable by direct analysis. Although cell culture allows qualitative analysis of the karyotype, potential selection and evolution during growth in vitro may yield misleading data. To determine whether aberrations observed in vitro are representative of the original lesion, chromosomal aberrations found after prolonged growth in vitro of two squamous cell carcinomas of the head and neck (SSCHN) were evaluated with fluorescence in situ hybridisation (FISH) on the original tumour nuclei.

METHODS

Specific karyotypic aberrations identified in cultures of two squamous cell carcinomas were targets for FISH analysis on tumour sections. Chromosome painting mixtures were selected based on in vitro karyotypic data. FISH was performed on cultured interphase and metaphase cells, and on histological sections from the original tumours.

RESULTS

The 9cen and 17cen probes yielded FISH signals consistent with the aneusomies predicted for the respective chromosomes from the culture karyotypes. Whole chromosome 9 paint confirmed the prior existence in the tumours of i(9p) and i(9q), although only the latter hybridised with the 9cen probe. FISH data also supported in vivo representation of the diploid and tetraploid tumour subclones observed in cultures. In tumour HFH-SCC-8a, FISH results were generally concordant between cultured interphase and metaphase cells and the histological sections, and improved the interpretation of marker chromosomes identified in culture.

CONCLUSION

The karyotypes obtained in these cases after prolonged passage in culture were consistent with the genetic alterations in the original tumours.

Surgical pathology specimens for gross examination only and exempt from submission: a College of American Pathologists Q-Probes study of current policies in 413 institutions

OBJECTIVE

To survey the scope of current written institutional policies for types of surgical pathology specimens exempt from submission to the laboratory and those that may be examined by gross inspection only.

DESIGN AND SETTING

In the first quarter of 1997, a total of 413 voluntary participant institutions enrolled in the College of American Pathologists Q-Probes quality improvement program completed a checklist of 115 proffered specimens. Also included was a questionnaire defining demographic, practice, and reimbursement variables.

MAIN OUTCOME MEASURES

The number and types of specimens exempt from submission and submitted for gross examination only based on written institutional policy rather than on unapproved actual practices.

RESULTS

Most institutions had a written policy for types of specimens deemed exempt from submission to pathology (87.1 %) and for types of specimens subject to gross examination only (76.6%). There was a wide range of numbers of specimen types with a median number of 17 (range, 2-40) in the exempt category and 29 (range, 6-57) in the category of gross examination only. Significantly higher absolute counts of specimens exempt from submission to pathology were reported by institutions with a greater surgical pathology volume in 1996 and by nonteaching institutions. No aspect of practice was associated with numbers of specimens for gross examination only.

CONCLUSIONS

This Q-Probes study creates a multi-institutional reference database of current practices to assist pathologists and clinical staff in the development of written guidelines pertaining to surgical pathology specimen submission exceptions and gross-only examinations.

Hyperparathyroidism-jaw tumor syndrome: the HRPT2 locus is within a 0.7-cM region on chromosome 1q

Hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant disease characterized by the development of multiple parathyroid adenomas and multiple fibro-osseous tumors of the maxilla and mandible. Some families have had affected members with involvement of the kidneys, variously reported as Wilms tumors, nephroblastomas, and hamartomas. The HPT-JT gene (HRPT2) maps to chromosome 1q25-q31. We describe further investigation of two HPT-JT families (K3304 and K3349) identified through the literature. These two expanded families and two previously reported families were investigated jointly for linkage with 21 new, closely linked markers. Multipoint linkage analysis resulted in a maximum LOD score of 7.83 (at recombination fraction 0) for markers D1S2848-D1S191. Recombination events in these families reduced the HRPT2 region to approximately 14.7 cM. In addition, two of these four study families (i.e., K3304 and K11687) share a 2.2-cM length of their (expanded) affected haplotype, indicating a possible common origin. Combining the linkage data and shared-haplotype data, we propose a 0.7-cM candidate region for HRPT2.

Thyroid transcription factor-1: immunohistochemical evaluation in pulmonary neuroendocrine tumors

Thyroid transcription factor-1 (TTF-1), a nuclear transcription protein selectively expressed in the thyroid, the diencephalon, and respiratory epithelium, is expressed in more than 90% of pulmonary small cell carcinomas (SCLCs) and in almost 75% of pulmonary non-small cell carcinomas (NSCLCs), but it is absent in typical pulmonary carcinoids (TCs). Therefore, it was thought that SCLC and NSCLC might share a common lineage, different from that of TC. TTF-1 expression in atypical pulmonary carcinoids (ACs) and large-cell neuroendocrine carcinomas (LCNECs) was not studied previously. We examined TTF-1 expression in 51 TCs, 9 ACs, 8 LCNECs, and 21 SCLCs with use of formalin-fixed material and heat-induced epitope retrieval. TTF-1 expression was seen in 18 (35%) of 51 TCs, all of the 9 ACs, 6 (75%) of the 8 LCNECs, and 20 (95%) of the 21 SCLCs. These results reinforce earlier findings of the excellent sensitivity of TTF-1 for SCLC, and they show similar sensitivity for AC and LCNEC, but they argue against the hypothesis that SCLC and TC are of different cell lineages. The ubiquity of TTF-1 expression in pulmonary NECs demonstrated in this study also argues against its use in their subclassification.

The MIB-1 tumor proliferation index in adult renal epithelial tumors with granular cytoplasm: biologic implications and differential diagnostic potential

The histologic diagnosis of adult renal epithelial neoplasms with prominent eosinophilic cytoplasm (renal oncocytoma, chromophobe renal-cell carcinoma (RCC), eosinophilic variant of clear-cell RCC, eosinophilic variant of papillary RCC, and collecting duct carcinoma), could be problematic in some cases because of overlapping morphologic features. Precise diagnosis is essential, however, because it often connotes a distinct biologic behavior. Proliferative activity has not been specifically investigated in this spectrum of renal tumors, so we studied the MIB-1 proliferation index in 20 renal oncocytomas, 12 chromophobe RCCs, 9 eosinophilic variants of papillary RCCs, and 13 eosinophilic variants of clear-cell RCCs. Our purpose was to identify the biologic potential of these renal tumors on the basis of MIB-1 tumor proliferation index and to ascertain whether that index had diagnostic value. Overall, nuclear grade correlated with MIB-1 tumor proliferation index (P=.03). The mean proliferation index progressively increased from renal oncocytomas (0.3) to chromophobe RCCs (0.8) to eosinophilic variants of papillary RCCs (2.2) to eosinophilic variants of clear-cell RCCs (4.1) (P=.002). None of the renal oncocytomas or chromophobe RCCs had an index greater than 2, whereas 8 of 13 eosinophilic variants of clear-cell RCCs had an index greater than 2; in 5 of these, it was more than 3. Thus, in the differential diagnosis between renal oncocytoma/chromophobe RCC and eosinophilic variant of RCC, an MIB-1 index of greater than 3 with appropriate morphologic correlation would strongly support the diagnosis of the latter. We also concluded that the progressive increase in MIB-1 tumor proliferation index across the spectrum of granular renal-cell neoplasms parallels the emerging data in the current literature concerning the biologic potential of adult renal epithelial tumors and justifies histologic categorization of adult renal epithelial neoplasms.

Interinstitutional comparison of surgical biopsy diagnosis turnaround time: a College of American Pathologists Q-Probes study of 5384 surgical biopsies in 157 small hospitals

OBJECTIVES

To study the turnaround time (TAT) for rendering diagnoses on routine biopsy specimens, to examine pathology practice variables that influence TAT, and to assess the level of surgeons' satisfaction with biopsy TAT.

DESIGN

Over a 3-month period, voluntary participants in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively collected TAT data on up to 20 biopsy specimens performed on elective surgical cases, completed questionnaires profiling their institution's practice characteristics, and had surgeons complete questionnaires indicating their satisfaction with biopsy report TAT.

SETTING AND PARTICIPANTS

One hundred fifty-seven private and public small hospitals located in 43 American states (n = 153), Canada (n = 1), and Australia (n = 3).

MAIN OUTCOME MEASURES

The routine surgical biopsy report TATs for 2 testing intervals, each commencing when surgeons acquired the biopsy specimens. One interval concluded when pathologists signed off the biopsy diagnoses, and the other concluded when surgeons received the hard-copy reports.

RESULTS

Pathologists signed off 85.9% of 5384 biopsy diagnoses by the second working day, and surgeons received 88.3% of the hard-copy reports by the fourth working day. In 90% of hospitals participating in this study, pathologists signed off half their biopsy diagnoses between the second and third postcollection days, and 90% of surgeons received half their final hard-copy reports by the fourth postcollection day. Institutional practice variables associated with fewer sign-off and/or hard-copy receipt TATs exceeding the institutional 90th percentile performance benchmarks included yearly surgical caseloads greater than 2000 cases per full-time equivalent pathologist, provision of pathology support services on site, and accreditation of the hospital by the Joint Commission on Accreditation of Healthcare Organizations and of the laboratory by the College of American Pathologists. Most (96.4%) surgeons indicated that they were satisfied with hard-copy TATs and that they believed most (98.1%) of the hard-copy TATs had no effect on the lengths of their patients' hospital stays.

CONCLUSIONS

Pathologists are capable of signing off most routine biopsy diagnoses within 2 working days and delivering the final hard-copy reports to surgeons within 4 working days (both intervals measured from the time that surgeons collect biopsy specimens). Most surgeons report they are satisfied with this level of performance.

Loss of 18q predicts poor survival of patients with squamous cell carcinoma of the head and neck

Tumor suppressor genes play an important role in normal growth regulation. Loss or inactivation of these genes has been implicated in the development of squamous cell cancer and progression of neoplasia. Previous studies in our laboratories have implicated chromosome 18 long-arm deletions as a possible marker of progression in head and neck squamous cell cancer (HNSCC). To test this hypothesis, we evaluated DNA from 67 HNSCC patients for loss of heterozygosity (LOH) at 18q loci, and for association of LOH with survival. Tumor and normal DNA were extracted from fresh tissue and paraffin blocks and were amplified by PCR using primers for three microsatellite repeat polymorphisms in 18q (D18S336, D18S34, and MBP). A total of 27 (40%) patients had LOH of 18q, and these patients had a statistically significantly poorer two-year survival compared to those without 18q LOH (30% vs. 63%; P = 0.008). In a Cox proportional hazards model in which time from diagnosis to death was the outcome variable, patients with 18q LOH had an unadjusted relative risk (RR) of death of 2.46 (P = 0.005). When 18q LOH was placed in a multivariate model controlling for possible confounders in the study, the RR for death was still elevated (RR = 2.10; P = 0.025). The observation of a prognostic association between 18q LOH and poor patient survival suggests that loss of an 18q tumor suppressor gene or genes is important in the progression of HNSCC.

Cutaneous verruciform xanthoma: a report of five cases investigating the etiology and nature of xanthomatous cells

Verruciform xanthoma is a rare clinicopathologic entity of uncertain etiology that occurs primarily in the oral mucosa. Aggregates of foam cells in the submucosal stroma or papillary dermis in association with verrucous epithelial hyperplasia are the hallmark of this lesion. Extraoral (cutaneous) occurrence of verruciform xanthoma is much rarer and has been reported mostly in the genital skin. Five cases of extraoral cutaneous verruciform xanthoma (three from the scrotum, one from the penis, and one from the nose) and one histologic "simulant" (from skin of the nose) were studied. The lesions were solitary, raised, or polypoid with cup-shaped craters filled with parakeratotic cells that blended into keratinocytes of an acanthotic and papillomatous epidermis. There was a neutrophilic infiltrate of varying intensity between plump parakeratotic cells and keratinocytes, near the surface of the epidermis. Aggregates of foam cells were present in the papillary dermis, which was highly vascular. A plasma cell predominant infiltrate was seen at the base in a bandlike fashion. Despite the architectural resemblance of verruciform xanthoma to verrucous mucocutaneous lesions related to human papillomavirus infection, it was not detected by either immunohistochemistry, in situ hybridization, polymerase chain reaction, or Southern blot analysis in any case. The foam cells were weakly positive for cytokeratin and for Factor XIIIa but negative for S-100 protein. The KP1 and Mac 387 immunostain showed focal weak staining in foam cells. We postulate that a cascade of events pursue after initial keratinocytic damage attracting neutrophils, with subsequent phagocytosis of necrotic keratinocytic debris by dermal dendrocytes, eventually leading to the ultimate manifestation of the lesion as verruciform xanthoma. The etiologic agent remains elusive, but based on our findings, we conclude that verruciform xanthoma is most likely not a human papillomavirus-associated squamoproliferative lesion and that the foam cells, a histologic hallmark of the lesion, are most likely derived from dermal dendritic cells.

Amended reports in surgical pathology and implications for diagnostic error detection and avoidance: a College of American Pathologists Q-probes study of 1,667,547 accessioned cases in 359 laboratories

OBJECTIVES

To evaluate amended report rates relative to surveillance methods and to identify surveillance methods or other practice parameters that lower amended report rates.

DESIGN

Participants in the 1996 Q-Probes quality improvement program of the College of American Pathologists were asked to prospectively document amended surgical pathology reports for a period of 5 months or until 50 amended reports were recorded. The methods of error detection were also recorded and laboratory and institutional policies surveyed. Four types of amended reports were investigated: those issued to correct patient identification errors, to revise originally issued final diagnoses, to revise preliminary written diagnoses, and to revise other reported diagnostic information that was significant with respect to patient management or prognosis.

PARTICIPANTS

Three hundred fifty-nine laboratories, 96% from the United States.

RESULTS

A total of 3147 amended reports in all four categories from a survey of 1,667,547 surgical pathology specimens accessioned during the study period were issued by the participants. The aggregate mean rate of amended reports was 1.9 per 1000 cases (median, 1.5 per 1000 cases). Of these, 19.2% were issued to correct patient identification errors, 38.7% to change the originally issued final diagnosis, 15.6% to change a preliminary written diagnosis, and 26.5% to change clinically significant information other than the diagnosis. Most frequently, a request from a clinician to review a case (20.5%) precipitated the error detection. Although not statistically significant, a higher amended report rate (1.6 per 1000) for all error types was associated with routine diagnostic slide review that was performed after completion of the surgical pathology report. This is compared to rates for institutions that had routine diagnostic slide review of cases prior to finalization of pathology reports (1.2 per 1000) and institutions that had no routine diagnostic slide review (1.4 per 100). Slide review of cases prior to completion of reports lowered the rate of amended reports issued for two types of amended reports: those in which the originally issued final diagnosis was changed and those in which information other than the diagnosis was changed for patient management or prognostic significance. Other laboratory practice variables examined were not found to be associated with the amended report rate.

CONCLUSIONS

There is an association between lower amended report rates and diagnostic slide review of cases prior to completion of the pathology report. The level of case review and type of case mix that is necessary for optimal quality assurance needs further investigation.

Colloidal iron staining in renal epithelial neoplasms, including chromophobe renal cell carcinoma: emphasis on technique and patterns of staining

Positive staining with Hale's colloidal iron stain, or modifications thereof, is considered a diagnostic feature for chromophobe renal cell carcinoma and has been used as a discriminatory feature to differentiate it from other renal tumors. We studied colloidal iron staining in 62 cases encompassing a wide histologic spectrum of renal neoplasms (14 chromophobe renal cell carcinomas, 19 renal oncocytomas, 11 each of granular variants and conventional clear cell renal cell carcinomas, and 7 eosinophilic variants of papillary renal cell carcinoma) to investigate the specificity of the stain for chromophobe renal cell carcinoma. In cases of chromophobe renal cell carcinoma, sections from two different areas were stained to ascertain whether there was any spatial variation in staining. Influence of staining techniques on the results also was investigated by staining each case of chromophobe renal cell carcinoma using two different methods: the traditional Hale's and a modified Mowry's technique, which treats sections with 3% acetic acid before adding the colloidal iron. Our results show that positive staining with colloidal iron stain is not limited to chromophobe renal cell carcinoma, however, a diffuse and strong, reticular staining pattern was observed only in cases of chromophobe renal cell carcinoma (14 of 14). The staining patterns were less consistent in all other renal neoplasms and differed from the reaction observed in chromophobe renal cell carcinoma. Most renal oncocytomas (16 of 19) had focal and weak, fine dustlike positivity, and all clear cell carcinomas showed focal, coarse, dropletlike positive staining (22 of 22), in addition to a focal, coarse, bubbly pattern in 5 of 11 clear cell subtypes. Although all seven cases of the eosinophilic variant of papillary renal cell carcinoma showed strong, coarse, dropletlike staining, most of the positivity was coincident with the Perl's (prussian blue) reaction, indicating that the staining was due to hemosiderin, which is frequently present in this histologic subtype of renal cell carcinoma. Staining intensity did not vary considerably among different areas of chromophobe renal cell carcinoma, but the modified Mowry's method yielded brighter and sharper reticular staining, as compared with the Hale's method. Our results show that in the appropriate morphologic context diffuse and strong reticular positivity using the modified Mowry's colloidal iron stain method is highly characteristic for chromophobe renal cell carcinoma. Treatment of sections with 3% acetic acid before adding the colloidal iron gives technically superior staining results.

Odontogenic ghost cell tumor: a case report with cytologic findings

Odontogenic ghost cell tumor is a rare, neoplastic form of calcifying odontogenic cyst (Gorlin cyst) whose cytologic features have not been previously reported. We present a case of odontogenic ghost cell tumor diagnosed by fine-needle aspiration biopsy (FNAB). The aspirate was characterized by (1) tissue fragments with basaloid epithelial cells, (2) "ghost" cells, (3) scattered multinucleated giant cells, (4) rare, eosinophilic, densely hyalinized "dentinoid" material in close association with the basaloid cells, and (5) calcific debris. The aspirate was diagnosed as "consistent with odontogenic ghost cell tumor." The cytologic features of odontogenic ghost cell tumor, as described, closely parallel the major histologic findings in this rare tumor. The differential diagnoses include other odontogenic tumors, squamous cell carcinoma, basaloid cell tumors of the salivary gland, and pilomatrixoma.

Small intestinal stromal tumors: a clinicopathologic study of 20 cases with immunohistochemical assessment of cell differentiation and the prognostic role of proliferation antigens

Small intestinal stromal tumors (SISTs), similar to their gastric counterpart, are complex because of their divergent cellular differentiation and because of the difficulty in accurately predicting their clinical outcome. We studied a series of 22 SISTs from 20 patients to characterize lineage and investigate prognostic morphologic parameters and possible histologic and immunohistochemical differences from gastric stromal tumors (GSTs) and to determine the potential prognostic value of proliferation markers. Cases were categorized into the three following groups based on mitotic count (MC) per 50 high-power fields and tumor size: (1) benign, n = 6 (< 5 MC, < 5 cm); (2) borderline, n = 6 (< 5 MC, > or = 5 cm); and (3) malignant, n = 10 (> or = 5 MC, any size). For the formalin-fixed, paraffin-embedded tissue sections, an immunohistochemical panel was used to characterize differentiation toward myogenic cells (pan-muscle specific actin [HHF-35], alpha-smooth muscle actin, and desmin), Schwann cells (S-100 protein), enteric glial (glial fibrillary acidic protein), and nerve cells (neurofilament). Cellular proliferative activity was assessed immunohistochemically using monoclonal antibodies to proliferating cell nuclear antigen (PCNA) and Ki-67 antigen (MIB-1) and a tumor proliferation index (TPI) was obtained as the percentage of positive-staining tumor nuclei. Clinical follow-up revealed that none of the benign tumors progressed (mean follow-up, 96 months). Half of the patients with borderline tumors were dead of disease (mean, 50.7 months), while 8 of 9 patients with a malignant tumor died of disease (mean, 24.6 months). By Cox Proportional Hazard Regression analysis, mitotic count, tumor size, and cellularity significantly predicted survival. PCNA, MIB-1, tumor necrosis, and atypia were not significant predictors of survival. All tumors stained with vimentin; 17 (77%) and 13 (59%) of the tumors showed immunoreactivity with muscle-specific actin markers (HHF-35) and alpha-smooth muscle actin, respectively. Only 1 tumor stained with desmin, and none stained with S-100 protein, neurofilament, or glial fibrillary acidic protein. Immunophenotypic characteristics did not differ among the 3 groups. The TPI for PCNA and MIB-1 significantly differed between benign and malignant tumors and between borderline and malignant tumors, but it failed to separate the benign and borderline groups. Compared with 52 cases of GST previously reported by us using the same criteria and antibody panel, these tumors were histologically and immunohistochemically indistinguishable. However, none of the 18 borderline GSTs progressed, while 3 of 6 patients with a borderline SIST died of the disease. Based on this series of 22 SISTs, we conclude the following: (1) MC, size, and cellularity are the best predictors of clinical outcome in SIST. (2) The majority of SISTs show smooth muscle differentiation based on their immunoreactivity with HHF-35 and alpha-smooth muscle actin). (3) The TPI for PCNA and MIB-1 correlated with MC but failed to predict survival for individual cases. (4) SISTs and GSTs are morphologically and immunohistochemically similar; however, SISTs seem to have greater malignant potential than GSTs of similar size.

Immunolocalization of three novel smooth muscle-specific proteins in salivary gland pleomorphic adenoma: assessment of the morphogenetic role of myoepithelium

Myoepithelial cells of salivary glands have a complex cytoskeletal immunophenotype. To elaborate the smooth muscle phenotype of salivary gland myoepithelium and to assess its contribution to the histogenesis of pleomorphic adenomas, we evaluated the immunohistochemical expression of three novel monoclonal antibodies (MAbs) to alpha smooth muscle actin (alpha-SMA), smooth muscle myosin heavy chains (SMMH), and calponin in formalin-fixed tissues of 65 pleomorphic adenomas (51 contained surrounding normal salivary gland as well). Different cell types within the pleomorphic adenomas were classified as inner tubular epithelial cells, myoepithelium-like cells (juxtatubular, cuboidal, and spindle), modified myoepithelium (myxoid, chondroid, hyaline), and transformed myoepithelium (solid epithelioid, squamous, basaloid-cribriform). Periacinar and periductal myoepithelial cells of all of the 51 normal salivary glands were diffusely stained by all of the 3 MAbs, whereas all of the acinar/ductal epithelial cells were entirely negative. Of 65 pleomorphic adenomas, 61 (94%) reacted to all of the 3 MAbs. None of the smooth muscle markers stained the inner-tubular epithelial cells. Both alpha-SMA and SMMH were essentially limited to the myoepithelium-like cells, whereas modified and transformed myoepithelia lacked these myofilaments. Calponin was found in 64 (98%) of the tumors, reacting to almost all of the myoepithelium-like cells, to 60% of the modified myoepithelium, and to 30% of the transformed myoepithelium. We found the expression of these smooth muscle-specific proteins in the neoplastic myoepithelium to be associated with morphologic differentiation. Alpha-SMA and SMMH are only expressed in better differentiated neoplastic myoepithelium. Calponin is the most sensitive marker of neoplastic myoepithelium, and its identification in different cell types of pleomorphic adenomas denotes a major histogenetic role of myoepithelial cells.

Antimitochondrial antibody (113-1) in the differential diagnosis of granular renal cell tumors

Abundant granular eosinophilic cytoplasm is a common feature of renal oncocytoma, chromophobe renal cell carcinoma, eosinophilic variant of papillary renal cell carcinoma, and the granular variant of clear cell renal cell carcinoma (RCC). Each of these entities has a unique architectural pattern and a distinctive molecular or cytogenetic profile. The chief reason for their distinction from one another is the difference in their biologic behavior. Careful and thorough light microscopic examination distinguishes most cases based on individual characteristic architectural and cytomorphologic features. However, precise characterization may be difficult in some cases because of overlapping morphologic features. We evaluated the antimitochondrial antibody 113-1 in an attempt to ascertain differences in immunostaining patterns in 57 cases of granular renal tumors, including 20 renal oncocytomas, 15 chromophobe RCCs, 13 granular variants of clear cell RCC, and nine eosinophilic variants of papillary RCC. Distinctive, and nearly exclusive, staining patterns were observed among the groups, with chromophobe RCC showing peripheral accentuation of coarse cytoplasmic granules (15 of 15), renal oncocytoma with diffuse and fine granularity (20 of 20), and granular variant of clear cell RCC with irregular cytoplasmic distribution of coarse granules (11 of 13). Staining was most intense in the eosinophilic variant of papillary RCC and was generally coarsely granular and diffuse. Staining patterns also differed in clear cell areas within chromophobe RCC and the granular variant of clear cell RCC. Although clear cells in the former group showed granular staining with peripheral accentuation, most of the clear cells in the latter lacked any staining. We conclude that, in addition to distinct cytoarchitectural features, immunostaining patterns with antimitochondrial antibody 113-1 appear to be a useful discriminatory adjunct in the complex differential diagnosis of granular renal cell tumors.

Prognostic significance of DNA ploidy and proliferation in 309 colorectal carcinomas as determined by two-color multiparametric DNA flow cytometry

BACKGROUND

Although DNA flow cytometry has been shown to be of independent value in determining the prognosis of colorectal carcinoma, a number of well-designed studies with contradictory findings have left unresolved the clinical significance of DNA ploidy and proliferation in biologically meaningful subsets of colorectal carcinoma cases.

METHODS

To evaluate the prognostic significance of DNA ploidy and proliferation as determined by flow cytometry in a prospective series of 309 human colorectal carcinomas with 4-6 years of follow-up, fresh tumors were mechanically dissociated into whole cell suspensions and dual fluorescence-labeled to allow gated analysis of subpopulations with phenotypic markers. Software programs with histogram-dependent algorithms employing background, aggregate, and debris correction were used in DNA and cell cycle quantitation. Data were analyzed according to recommendations of the 1992 DNA Flow Cytometry Consensus Conference.

RESULTS

None of the clinical, site, or staging parameters, including TNM stage variables, correlated with any flow cytometric DNA ploidy or proliferation measurement. Tumors classified as DNA aneuploid or tetraploid, by any definition, did not differ in prognosis or correlate with stage or any pathologic parameter. Univariate Kaplan-Meier survival analysis showed prognostic significance of the following: Dukes staging, individual components of TNM stage (tumor depth, lymph node status, and metastasis), vascular invasion, histologic pattern of tumor infiltration, and peritumoral lymphocytic inflammation. DNA ploidy status and proliferation measurements were not predictive of survival for the overall group or within any particular stage. Only Dukes Stage D (metastasis), vascular invasion, and depth of invasion (T classification) were significant independent predictors of survival in multivariate Cox regression models.

CONCLUSIONS

In this analysis, DNA ploidy and proliferation measurements were not predictive of survival in any stage of colorectal carcinoma. However, clinical and pathologic documentation of staging and select histopathologic observations were significant predictors of survival in univariate and multivariate analyses.

Interinstitutional comparison of frozen section turnaround time. A College of American Pathologists Q-Probes study of 32868 frozen sections in 700 hospitals

OBJECTIVES

To study the intraoperative turnaround time for performing a frozen section (FS) and to examine pathology practice variables that influence it.

DESIGN

Over a 4-month period in 1995, participants in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively collected data on up to 30 FS procedures performed on elective inpatient surgical cases and completed questionnaires profiling their FS practice characteristics.

SETTING

Surgical pathology laboratories serving private and public hospitals.

PARTICIPANTS

Seven hundred institutions located in North America (667), Australia (12), New Zealand (1), the United Kingdom (3), Hong Kong (1), Mexico (1), and Norway (1).

MAIN OUTCOME MEASURES

The 90% FS block completion time defined as the time interval, in minutes, within which the fastest 90% of all FS blocks were completed, measured from the time pathologists received FS specimens to the time they communicated FS results to the surgeon.

RESULTS

Participants submitted data on 32868 FS blocks. Ninety percent of FS procedures were completed within 20 minutes. Frozen section turnaround times exceeding 20 minutes, termed outlier turnaround times, were more likely to occur when more than one pathologist participated in the FS diagnosis, pathology residents and medical students participated in the FS procedure, the pathologist had to retrieve and review previous case material during the FS procedure, the pathologist simultaneously received additional specimens from other FS cases, the pathologist was unable to reach a final FS diagnosis, and when technical problems occurred during the FS procedure. Seventy percent of all participating hospitals completed 90% of their frozen sections within 20 minutes. The institutional 90% completion times were shorter for hospitals containing 300 or fewer occupied beds than for those containing more than 300 occupied beds.

CONCLUSIONS

The data suggest that 90% of FS block turnaround times can be performed within 20 minutes, measured from the time that pathologists receive FS specimens to the time that pathologists return FS diagnoses to surgeons.

Mammographically directed breast biopsies: a College of American Pathologists Q-Probes study of clinical physician expectations and of specimen handling and reporting characteristics in 434 institutions

OBJECTIVES

To determine (1) the information that clinical physicians want in surgical pathology reports of biopsies performed for mammographic abnormalities, (2) how specimens are received and processed, and (3) what information is actually present in pathology reports.

DESIGN

The standard data collection and questionnaire format of the College of American Pathologists' Q-Probes quality improvement program was used. Laboratories (1) surveyed clinical physicians working in selected specialties involved in the care of patients with breast disease concerning what information they wanted in a surgical pathology report, (2) documented laboratory specimen handling for 20 consecutive breast biopsy tissues obtained to investigate mammographic abnormalities, and (3) documented the information content of surgical pathology reports of these cases.

PARTICIPANTS

Four hundred thirty-four participating laboratories surveyed 1469 clinical physicians and collected information on 7300 cases regarding specimen processing and report content.

RESULTS

Clinical physicians were unanimous in the majority of items they desired for patient care. The information, however, differed depending on the diagnosis. In processing of tissues, 89% of specimens were received without fixative. In 83% of cases, radiographs were performed. Eighty-two percent of specimens were marked in some manner, but in only 45% of cases was a report of the radiographic abnormality given to the Pathology Department. The median number of blocks used to sample the lesion and the whole specimen was three and six blocks, respectively. The latter correlated with specimen size. Fifty-seven (13%) surgical pathology laboratories had radiography equipment. Radiographs of specimens and tissue blocks were made in 5% and 4% of cases, respectively. Correlation of a mammographic abnormality with a microscopic finding was documented in 62% of reports. In 92% of malignant cases the margin status was reported, and 77% of reports contained the lesion size. Eighty-three percent of reports with invasive carcinoma stated the tumor grade, and 76% stated the extent of intraductal carcinoma. The percentage of reports containing information items was significantly higher (P < .05) for institutions using checklists.

SUMMARY

This multi-institutional Q-Probes study describes the current clinical expectations and laboratory practices associated with mammographically directed biopsies. Disparities between pathology reporting and clinician desires, as well as radiology and laboratory specimen handling practices, have been identified and may help focus future quality improvement efforts.

Interinstitutional comparison of frozen section consultation in small hospitals: a College of American Pathologists Q-Probes study of 18,532 frozen section consultation diagnoses in 233 small hospitals

OBJECTIVE

To study pathology intraoperative consultation practices and the accuracy of diagnoses made by frozen section.

DESIGN

In 1994, participants in the College of American Pathologists Q-Probes laboratory quality improvement program each completed questionnaires and prospectively collected data on up to 20 frozen section procedures performed over a 5-month period.

SETTING

Surgical pathology laboratories serving private and public hospitals with 300 or fewer occupied beds.

PARTICIPANTS

Two hundred thirty-two North American institutions and one New Zealand institution.

MAIN OUTCOME MEASURES

The discordance and deferral rates of frozen section diagnoses and the reasons for frozen section discordance relative to corresponding diagnoses made on permanent (paraffin) sections. Calculation of frozen section discordance rates excluded diagnoses of subtypes or grade of malignancy, biopsies on specimens in which there was no gross lesion (eg, mammographic specimens), thyroid follicular lesions, tissue taken only to determine adequacy for other studies (eg, estrogen-binding proteins), and frozen sections performed to evaluate margins of specimens oriented en face.

RESULTS

Out of 18,532 frozen section diagnoses performed on 327,884 surgical cases, 859 (4.6%) diagnoses were deferred until permanent sections were available for review; 17,357 (98.2%) nondeferred diagnoses agreed with, and 316 (1.8%) disagreed with, those diagnoses rendered on permanent sections. The most common cause of discordance was underdiagnosis of neoplasia, usually due to block- or tissue-sampling errors.

CONCLUSIONS

We recommend that laboratories routinely monitor frozen section discordance, cut additional sections deeper into the frozen block and/or sample additional tissue when the initial frozen section diagnosis is negative or nonproductive, reconcile all discordant frozen section diagnoses in the final report, and periodically assess the value of performing frozen section examinations.

Quality assurance of autopsy face sheet reporting, final autopsy report turnaround time, and autopsy rates: a College of American Pathologists Q-Probes study of 10003 autopsies from 418 institutions

OBJECTIVE

To develop a multi-institutional reference database of autopsy practice and performance for quality improvement purposes.

DESIGN

In 1990, participants in the Q-Probes quality improvement program of the College of American Pathologists (CAP) each retrospectively evaluated the 25 most recently completed consecutive autopsy reports and determined the number of deaths and autopsies that occurred in their institutions during 1989.

SETTING

Hospital-based autopsies excluding forensic cases and stillborn infants.

PARTICIPANTS

Four hundred ten institutions in the United States and eight institutions in Canada.

MAIN OUTCOME MEASURES

Completeness of face sheet information contained in final autopsy reports, turnaround time for completion of final reports, and institutional autopsy rates.

RESULTS

In the aggregate database of 10003 autopsies, the following six data items (from a total of 21) were present in 95% to 100% of the final autopsy reports in at least 85% of the participating institutions: institution where autopsy was performed, patient's name, patient's sex, autopsy number, autopsy date, and prosecter's name. The turnaround times for the final autopsy reports were as follows: 30 days or less in 47.6% of the cases, 31 to 60 days in 28.8%, and more than 60 days in 23.7%. A higher median percentage of autopsy final reports were completed in 30 days or less in institutions with the following characteristics: nonteaching (P < .004), no pathology residency program (P < .002), and rural location (P < .027). A lower number of autopsies performed in 1989 was associated with a higher median percentage of final reports completed in 30 days or less (P < .007). The aggregate autopsy rate for all participating institutions was 12.4%, and the median rate was 8.3%. Median autopsy rates for teaching institutions and institutions with pathology residency training programs were 15% and 19%, respectively.

CONCLUSIONS

This multi-institutional study identified a core group of face sheet data items that were consistently present on final autopsy reports. However, the majority of the face sheet data items examined were inconsistently recorded. Approximately 75% of final autopsy report turnaround times were within the standard established by the Joint Commission on Accreditation of Healthcare Organizations. Nearly two thirds of the institutions reported autopsy rates for 1989 of 0% to 10%.

Extraneous tissue in surgical pathology: a College of American Pathologists Q-Probes study of 275 laboratories

OBJECTIVE

To develop a multi-institutional reference database of extraneous tissue (contaminants) in surgical pathology.

DESIGN

In 1994, participants in the College of American Pathologists Q-Probes quality improvement program performed prospective and retrospective evaluations of extraneous tissue found in surgical pathology microscopic sections for a period of 4 weeks or until 1000 slides were reviewed in each participating laboratory.

PARTICIPANTS

Two hundred seventy-five surgical pathology laboratories institutions, predominantly from North America.

MAIN OUTCOME MEASURES

Extraneous tissue contamination rate for slides in prospective and retrospective reviews; staffing and practice procedures; location of extraneous tissue on slides; type of extraneous tissue (normal, abnormal, nonneoplastic, neoplasm, microorganisms, etc); class of extraneous tissue (slide or block contaminants); source of extraneous tissue (different or same case); origin of extraneous tissue (pathology laboratory, physician's office or operating room); and degree of diagnostic difficulty caused by extraneous tissue.

RESULTS

Three hundred twenty-one thousand seven hundred fifty-seven slides were reviewed in the prospective study and 57083 slides in the retrospective study. There was an overall extraneous tissue rate of 0.6% of slides (2074/321757) in the prospective study and 2.9% of slides (1653/57083) in the retrospective study. Of those slides with extraneous tissue, the extraneous tissue was located near diagnostic tissue sections in 59.5% of the slides reviewed prospectively and in 25.3% of slides reviewed retrospectively; deeper sections were performed to evaluate extraneous tissue in 12.2% of prospective cases and in 3.1% of retrospective cases. Of the laboratories, 98% had written guidelines for changing solution in tissue processors, and 64.9% had guidelines for maintaining water baths free of extraneous tissue. A total of 98.9% used lens paper, filter bags, or sponges for processing fragmented and small specimens. Written protocols for documentation of extraneous tissue in surgical pathology reports were established in 6.1% of laboratories, for removal of extraneous tissue from blocks in 5.7%, and for removal of extraneous tissue from microscopic slides in 4.7%. In 24% of laboratories no comment or record was kept to document extraneous tissue. Extraneous tissue consisted of neoplasm in 12.7% of the prospectively reviewed slides and in 6.0% of the retrospectively reviewed slides. For the prospective study, 59.4% of extraneous tissue was classified as slide contaminants, and 28.4% was found to be contaminants within the paraffin block; for the retrospective study, 72.9% was classified as slide contaminants and 15.9% as block contaminants. For the prospective study, 63.2% of extraneous tissue was presumed to be from a different case, and in the retrospective study, 48.5% was presumed to be from a different case. Over 90% of extraneous tissue was thought to originate from the pathology laboratory. The degree of diagnostic difficulty caused by extraneous tissue was judged to be severe in 0.4% of slides in the prospective study and 0.1% of slides in the retrospective study. In the prospective study, it could not be determined whether the tissue in the diagnostic sections was extraneous in 0.6% of slides, and in the retrospective study, it could not be determined whether tissue in the diagnostic sections was extraneous in 0.1%.

CONCLUSIONS

This study has documented the frequency, type, origin, source, and diagnostic difficulty of extraneous tissue and presents benchmarks of extraneous tissue experienced in the general practice of surgical pathology.

Quality assessment in anatomic pathology in the cost-conscious era

In this cost-conscious era, quality assessment activities in anatomic pathology are required not only to assure that quality practices result in satisfaction of accreditation standards but also to focus quality management to improve services in an economically competitive manner. Selected high yield monitoring activities that provide comparison to reference databases for benchmarking performance and adoption of practice variables effective in the best laboratories are recommended.

Interinstitutional comparison of frozen section consultations. A college of American Pathologists Q-Probes study of 90,538 cases in 461 institutions

OBJECTIVE

To assess concordant, discordant, and deferred diagnosis rates from frozen sections; to determine reasons for discordance; to identify pathologic processes associated with discordant diagnoses; to determine false-positive or false-negative rates for neoplasms; and to identify anatomic sites associated with discordant frozen section diagnoses.

DESIGN

Q-Probes study of the College of American Pathologists.

PARTICIPANTS

Four hundred sixty-one institutions participating in the Q-Probes program from November 1, 1990, through March 31, 1991.

MAIN OUTCOME MEASURES

Concordant and discordant diagnosis rates.

RESULTS

The frozen section concordance rate for diagnoses from the aggregate group was 98.58% and the discordance rate was 1.42%, when uncorrected for deferred diagnoses. During the study period, participating institutions accessioned 1,693,331 surgical pathology cases; 90,538 of these cases were evaluated by frozen section consultation, resulting in the examination of 121,668 specimens and 148,506 frozen section blocks. The majority of the frozen section discordances occurred because of misinterpretation of the original frozen section (31.8%), presence of diagnostic tissue in permanent sections of the frozen block when the frozen section was negative (30.0%), and presence of diagnostic tissue in the portion of the specimen not sampled by the frozen section (31.4%). Of the discordant diagnoses, 67.8% had false-negative diagnoses for neoplasm. The pathology processes and anatomic sites represented in discordant diagnoses are also evaluated.

CONCLUSIONS

High diagnostic accuracy of frozen section consultations was demonstrated. Frozen sections are used to evaluate a variety of pathologic processes and anatomic sites.

The effect of number of histogram events on reproducibility and variation of flow cytometric proliferation measurement

Sources of variation in synthesis phase fraction (SPF) calculation were studied, and the number of histogram events was found to be an important quality control consideration. Six cell cycle models (CCMs) for histograms composed of 1,000 to 20,000 events were compared. All CCMs were cytometer based, or available in Multicycle (MC) software. The experiment consisted of five consecutive acquisitions, on the same day, of the same propidium iodide (PI) stained sample of T24 human cell line, at each of nine "landmarks" between 1,000 and 20,000 events. The authors found (1) all CCMs evaluated required > or = 5,000 events for accurate, reproducible SPF; and (2) in the 5,000-20,000 event range the MC models provided the most accurate, reproducible SPF values. Therefore, histogram-dependent curve fitting models may enhance clinical applications of FCM proliferation measurements. The authors conclude that histogram rejection criteria for S-phase analysis should be established, and that two-color multiparametric DNA analysis "live" gating with tissue specific markers may assure acquisition of sufficient events for accurate SPF.

Lack of correlation between flow cytometric and immunohistologic proliferation measurements of tumors

We compared different means of assaying tumor proliferative activity by either flow cytometric or immunohistologic methods in formalin-fixed, paraffin-embedded blocks. A series of 84 Dukes' stage B colorectal carcinomas were examined to identify high-risk patients who may potentially benefit from adjuvant therapy. Flow cytometric analysis was performed by a modified Hedley method with a combined S+G2/M phase proliferative fraction calculated by means of a rectangular model after debris subtraction. Immunohistologic tumor proliferative activity was analyzed by means of serial step sections from the same blocks used for flow cytometric examination with antibodies to proliferating cell nuclear antigen (PCNA) and Ki-67 (MIB-1). Mean with standard deviation and (range) tumor proliferative activity measurements were: flow cytometric analysis: proliferative fraction = 14.8% +/- 5.3 (5-27%), PCNA = 43.2% +/- 21.2 (4-90%), and MIB-1 = 16.2% +/- 10.8 (2-47%). No correlation was found between flow cytometric proliferative fraction and immunohistologic tumor proliferation measurement or between PCNA and MIB-1 staining indices. Lack of correlation between flow cytometric and immunohistologic findings may be related to the use of archival formalin-fixed paraffin-embedded tissue for flow cytometric evaluation, with resultant increased debris and decreased accuracy of cell cycle calculations. Discordance between PCNA and MIB-1 may reflect inherent problems with anti-PCNA antibody staining of formalin-fixed tissues whereby anti-PCNA clone PC-10 detects non-replicon associated PCNA in formalin-fixed tissues. Prospective studies using fresh tissue with two-color multiparameter flow cytometric analysis and histogram-dependent background fitting may help to clarify the relationship between findings of tumor proliferation as analyzed by flow cytometric and by immunohistologic techniques.

Quality assurance of autopsy permit form information, timeliness of performance, and issuance of preliminary report. A College of American Pathologists Q-Probes study of 5434 autopsies from 452 institutions

OBJECTIVE

To develop a multi-institutional reference database of autopsy practices and performance for quality improvement purposes.

DESIGN

In 1992, participants in the Q-Probes quality improvement program of the College of American Pathologists each prospectively evaluated consecutive autopsies performed over a 6-month period, up to a maximum of 20 autopsies per institution.

SETTING

Hospital-based autopsies, excluding forensic cases and stillborn infants.

PARTICIPANTS

Four hundred forty-nine North American institutions and three Australian laboratories.

MAIN OUTCOME MEASURES

Completeness of information contained on autopsy permit forms, timeliness of autopsy performance between patients' deaths and autopsy prosections, and turnaround time of preliminary autopsy reports.

RESULTS

In the aggregate database of 5434 autopsy cases, 7 of 11 selected data items were consistently present on autopsy permit forms in 80% of the participating institutions. The median percentage of autopsies in which permission was given for an unrestricted (complete) autopsy was 71%. The following median time intervals were obtained: time of the patient's death to time the autopsy permission was received, 5 hours, 23 minutes; time the autopsy permission was received to time the prosection was started, 3 hours, 30 minutes; and time of the patient's death to time the prosection was started, 14 hours, 52 minutes. Differences were observed in some time intervals when the participating institutions were grouped by reported demographic characteristics. Preliminary reports were completed in 2 days or less in 80.9% of the autopsies.

CONCLUSIONS

Through this multi-institutional study, we have documented a consistent core of autopsy permit form information requested and a wide range of time intervals elapsed between the patients' deaths and autopsy performance. We have also established that the majority of participating institutions meet the College of American Pathologists' laboratory accreditation standard of providing a documented preliminary report of the gross pathologic diagnoses submitted to the attending physicians and institutional record within 2 working days following autopsy completion.