Prospective and retrospective review of gynecologic cytopathology: findings from the College of American Pathologists Gynecologic Cytopathology Quality Consensus Conference working group 2

CONTEXT

Two quality metrics for gynecologic cytology are the subject of this review: "prospective rescreening" and "retrospective rescreening."

OBJECTIVE

To offer consensus best practice approaches based on the College of American Pathologists' laboratory-based survey funded by the Centers for Disease Control and Prevention.

DESIGN

The College of American Pathologists submitted a paper-based survey to 1245 laboratories. After review of initial results, follow-up Web-based survey results, and a literature review, consensus best practice statements were presented at a national consensus conference. These statements were discussed and voted upon by conference participants. Results.-A total of 541 laboratories responded to survey questions about prospective and retrospective rescreening. Most laboratories (>85%) prospectively rescreen more than 10% of Pap tests interpreted as negative for intraepithelial lesion or malignancy. Most (72%) report inclusion of less than 20% high-risk cases. Most laboratories use multiple measures to define "high risk." Most laboratories (96.2%) retrospectively rescreen Pap tests from the preceding 5 years only. In most laboratories (71.4%) only Pap test results with high-grade squamous intraepithelial lesion or worse prompt retrospective review.

CONCLUSIONS

The number of Pap tests from high-risk patients should be maximized in prospective and retrospective rescreening. Unsatisfactory Pap tests should also be included. All readily identifiable high-risk human papillomavirus-positive cases with an interpretation of negative for intraepithelial lesion or malignancy should be prospectively rescreened. Cervical biopsy results with high-grade cervical intraepithelial neoplasia or worse (CIN 2+) should trigger retrospective rescreening. Regular feedback should be provided to cytotechnologists and cytopathologists. Upgraded diagnoses from negative for intraepithelial lesion or malignancy to atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion, should be monitored.

Distinguishing Carcinoid Tumor of the Mediastinum From Thymoma: Correlating Cytologic Features and Performance in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology

Context.—The cytologic features of carcinoid tumor in mediastinal fine-needle aspiration are well described. Nevertheless, this tumor may be difficult to distinguish from thymoma in this site.

Objective.—We sought to correlate the cytologic features of carcinoid tumor of the mediastinum in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology with the frequency of misclassification as thymoma.

Design.—We reviewed 446 interpretations from 18 different cases of carcinoid tumor in mediastinum and correlated the cytologic features with performance.

Results.—Cases were more frequently classified as thymoma (158 responses, 35%) than as carcinoid tumor (126 responses, 28%). The best-performing case was classified as carcinoid tumor only 56% of the time. Three cytologic patterns were identified. Four cases consisted of isolated round cells with salt-and-pepper chromatin. Four cases consisted of isolated spindle and round cells with salt-and-pepper chromatin. The remaining 10 cases consisted of cohesive fragments of crowded cells with finely granular chromatin showing numerous pyknotic cells mimicking lymphocytes. Prominent vasculature patterns were not a feature of any of the cases. There was no correlation between any pattern and the rate of classification as carcinoid tumor or thymoma (P > .05).

Conclusions.—Carcinoid tumor of the mediastinum is frequently misclassified as thymoma in this program. Although some cytologic patterns resemble thymoma, the lack of correlation of these patterns with performance suggests that at least part of the reason for misclassification may be failure to consider the correct diagnosis or a lack of familiarity with discriminating cytologic criteria.

Bethesda 2001 implementation and reporting rates: 2003 practices of participants in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology

CONTEXT

The 2001 Bethesda System for the reporting of cervical cytology specimens and the use of new liquid-based and human papillomavirus testing technologies have led to changes in cervical cytology reporting practices.

OBJECTIVES

To analyze current laboratory reporting practices using Bethesda 2001 terminology and to compare results with previous survey data from 1996.

DESIGN

Questionnaire survey mailed to 1751 laboratories in mid-2003.

PARTICIPANTS

Laboratories enrolled in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology.

RESULTS

Of the 759 responding laboratories, most (85.5%) had implemented Bethesda 2001 terminology, and the majority had adopted major changes, such as elimination of the benign cellular changes category and the satisfactory but limited category. The median reporting rate for low-grade squamous intraepithelial lesion was 2.1%, compared to a 1996 median rate of 1.6%, but the increase was confined to liquid-based preparations. Reporting rates for high-grade squamous intraepithelial lesion (median, 0.5%) and atypical squamous cells (ASC) had changed little. Most ASC cases were subclassified as "undetermined significance" (median, 3.9%) with ASC, cannot exclude high-grade SIL accounting for a minority (median, 0.2%). The median ratio of ASC to squamous intraepithelial lesions and carcinomas (SIL+) was 1.4 and was lower than the 1996 median ratio of 2.0. Median reporting rates for squamous abnormalities for 2002 were noted to be significantly higher for liquid-based preparations than for conventional smears, while median ASC/SIL+ ratios were lower. Most laboratories offer human papillomavirus testing, but almost half (47%) of laboratories do not know the percentage of positive testing results in patients with ASC.

CONCLUSIONS

Most laboratories have implemented Bethesda 2001 terminology. New criteria and liquid-based methods have led to an increase in low-grade squamous intraepithelial lesion reporting rates and a decrease in ASC/ SIL+ ratios when compared with 1996 data. Liquid-based preparations have higher median squamous intraepithelial lesion rates and lower ASC/SIL+ ratios than conventional smears.

Cytologic features of high-grade squamous intraepithelial lesion in ThinPrep Papanicolaou test slides: comparison of cases that performed poorly with those that performed well in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology

CONTEXT

Conventional Papanicolaou (Pap) test slides of high-grade squamous intraepithelial lesions (HSILs) that are frequently misdiagnosed are known to have relatively few dysplastic cells. Whether this is true of cases of HSIL in ThinPrep Pap Test specimens is not known.

OBJECTIVE

To determine if cases of HSIL in ThinPrep specimens that are frequently missed have relatively few dysplastic cells.

DESIGN

The cytologic features of 16 ThinPrep cases of HSIL that performed poorly in the College of American Pathologists Interlaboratory Comparison Program were compared with 22 ThinPrep Pap Test cases that performed extremely well.

RESULTS

Significantly more cases that performed poorly had fewer than 250 dysplastic cells (13/16) than cases that performed well (3/22) (P <.001).

CONCLUSION

ThinPrep Pap Test cases with a diagnosis of HSIL that performed poorly in this program had significantly fewer dysplastic cells than those that performed well.

Cytologic features of squamous cell carcinoma in ThinPrep slides: evaluation of cases that performed poorly versus those that performed well in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology

CONTEXT

Although the cytologic features of squamous cell carcinoma in ThinPrep specimens are well known, whether these features are different in cases that are easily identified than in cases that are more difficult to identify is not known.

OBJECTIVE

To determine the cytologic features of squamous cell carcinoma in ThinPrep specimens that are easy to identify versus those that are difficult.

DESIGN

The cytologic features of 6 cases of squamous cell carcinoma that performed poorly in the College of American Pathologists Interlaboratory Comparison Program were compared with 14 cases that performed extremely well.

RESULTS

After evaluation of multiple criteria, 7 different cytologic features were analyzed based on review by a consensus panel blinded to the performance of the cases. The feature that was most strongly associated with cases that performed poorly was the presence of Trichomonas vaginalis (5/6 [83%] vs 0/14; P <.001). The presence of marked nuclear pleomorphism was more common in cases that performed well (4/14 [28%] vs 0/6; P =.27), but was not significant. The number of tumor cells, the number of normal cells, and the presence of keratinization, pleomorphism, nucleoli, and diathesis were not significant. The most common misdiagnosis after Trichomonas vaginalis was reparative change.

CONCLUSIONS

The presence of Trichomonas is characteristic of cases of squamous cell carcinoma in ThinPrep slides that are often misdiagnosed in this program. While Trichomonas is identified by participants in some of these cases, a significant percentage of participants interpreted the findings as reparative, without identifying the organism. These results emphasize the importance of distracting factors, whether identified or not, in evaluating gynecologic cytology.

Atypical endocrine tumors of the lung: a histologic, ultrastructural, and clinical study of 19 cases

Lung cancers are divided by light microscopic criteria into several categories, but only two categories are recognized clinically--small cell and non-small cell carcinomas. Transmission electron microscopy has revealed unexpected complexity within each category, blurring the distinctions between them. The present study was undertaken to determine the incidence of dense-core, neuroendocrine-type granules in lung tumors diagnosed by light microscopy as non-small cell carcinomas, i.e., atypical endocrine tumors, and the clinical significance of their identification. Of 205 consecutive primary and metastatic lung cancers, 19 (9 per cent) diagnosed as non-small cell carcinomas by light microscopy were seen to contain neuroendocrine-type granules by electron microscopy and thus were reclassified as atypical endocrine tumors of the lung. Staining with silver stains, periodic acid-Schiff (PAS), PAS with diastase digestion, and mucicarmine was positive in 18, 15, 14, and eight of the 19 cases, respectively. Electron microscopy revealed glandular differentiation in 12 cases and tonofilaments in eight cases, although none of the tumors met the criteria for identification as squamous cell carcinomas. Clinically, the cancers appeared to resemble non-small cell carcinoma more closely than small cell carcinoma. Median survival (12 months) and response to combination chemotherapy (22 per cent) were in the range reported for non-small cell carcinoma. There were no complete responses, despite the use in some cases of regimens active against small cell carcinoma. However, one patient, the only one to date so treated, had a dramatic response to streptozotocin/5-fluorouracil, suggesting that, as in metastatic carcinoid, this combination may have value in the treatment of atypical endocrine tumors of the lung.

Myeloma cells in the urine

We report two unusual manifestations of multiple myeloma in a 71-year-old man. Late in the course of his disease, myeloma cells were observed in the patient's urinary sediment. At post mortem, the source of the cells was found to be a plasmacytoma of the urinary bladder. To our knowledge, this appears to be the first report of a clearly demonstrable anatomic source for myeloma cells in the urine.