Accuracy and reliability of frozen section diagnosis in a series of 672 nonpalpable breast lesions

Utility and diagnostic accuracy of intraoperative frozen sections in hepato-pancreato-biliary surgical pathology

BACKGROUND AND PURPOSE

Hepato-pancreato-biliary (HPB) surgeries are one of the most challenging and complex procedures. Intraoperative frozen section (IFS) diagnosis plays a pivotal role in management decisions. Comprehensive large cohort studies evaluating utility of IFS in HPB malignancies are lacking. This study aimed to evaluate the accuracy of frozen section analysis and to analyse discrepancies and impact of IFS on the surgical decisions.

PATIENTS AND METHODS

This was a retrospective study of IFS received for the HPB specimens between years 2009 and 2021. The results were compared to the permanent sections to evaluate diagnostic accuracy, sensitivity and specificity. Indications, disagreements and impact on the surgical management were analysed.

RESULTS

A total of 1008 specimens were evaluated: bile duct margin (279; 27.7%), gallbladder (203; 20.1%), liver lesions (125 cases; 12.4%), lymph nodes (147; 14.6%), pancreatic margin (120; 11.9%) and deposits (134; 13.3%). IFS were diagnosed as negative for malignancy (805; 79.9%), positive for dysplasia (8; 0.8%), suspicious for malignancy (6; 0.6%) and positive for malignancy (189; 18.8%). The overall diagnostic accuracy was 98.4%, and the discordant rate was 1.6%. The sensitivity, specificity, positive predictive value and negative predictive value were 94.7%, 99.4%, 97.5% and 98.6% respectively. The most important reason of discordant results was technical, followed by interpretational and sampling errors.

CONCLUSION

The study demonstrates high diagnostic accuracy (98.4%) of IFS in a large dataset of HPB specimens. This comprehensive analysis apprises of the indications, errors and the impact of IFS diagnosis on subsequent HPB surgical management.

Diagnostic Value of Intraoperative Frozen Section in Breast-Conserving Surgery: A Systematic Review and Meta-analysis

Context: According to previous studies, using the frozen section procedure during breast surgery reduces the rate of error and the need for re-surgery. We aimed at performing a comprehensive systematic review and meta-analysis to provide reliable evidence on the diagnostic value of frozen section procedures in breast-conserving surgery (BCS). Data Sources: A thorough search was performed in PubMed, Embase, Cochrane Library, and Web of Science databases for human diagnostic studies that used the frozen section in BCS. Meta-analyses were done to find the sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR). Study Selection: Human diagnostic studies used the frozen section in breast-conserving surgery and studies that reported the sensitivity and specificity of the frozen section in BCS or contained data that could be calculated the desired parameters were selected for this meta-analysis. Data Extraction: Assessment of studies quality was done and data was extracted from included papers. Then, the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool was used to assess the quality of included papers. Results: Thirty-five papers were entered into our study. The meta-analysis indicated the high sensitivity (83.47, 95%CI 79.61 - 87.32) and specificity (99.29, 95%CI 98.89 - 99.68) for the frozen section in BCS, which resulted in an accuracy of 93.77 (95%CI 92.45 - 95.10). We also found a significant PPV (93.26, 95%CI 91.25 - 95.27), NPV (92.17, 95%CI 90.22 - 94.11), PLR (7.99, 95%CI 6.01 - 9.96), and NLR (0.18, 95%CI 0.14 - 0.23). Conclusions: The findings showed that intraoperative frozen section analysis has high sensitivity and specificity for evaluating lumpectomy margins in patients with early-stage breast cancer and significantly reduces the need for re-operation. Accordingly, re-operation costs are not imposed on the patient and reduce the anxiety of the patients.

Pitfalls in Frozen Section Interpretation: A Retrospective Study of Palpable Breast Tumors

Aims and background

The use of frozen sections for purposes of diagnosis is recognized to involve a degree of uncertainty. A retrospective study of breast specimen frozen section diagnoses was undertaken in order to analyse the major pitfalls.

Methods

Hard copy files from our archives relating to symptomatic (palpable) breast specimens obtained between 1983 and 1996 were reviewed.

Results

The review revealed 23 errors among the diagnoses on 2110 frozen specimens. Twenty-two of them were false-negative and 1 (a case of multiple intraductal papillomatosis with atypical ductal hyperplasia) was false-positive for malignancy. The factors contributing to the pitfalls were: 1) misinterpretation; 2) poor quality of the frozen sections (artifacts making the diagnosis difficult); 3) sampling errors during sectioning; 4) ignorance of the macroscopic features; 5) lesions difficult to interpret; 6) ductal carcinoma in situ as the only lesion in the specimen; and 7) sections not deep enough. Several of the factors sometimes occurred simultaneously.

Conclusions

Although the number of errors is relatively low, more stress should be placed on the preoperative diagnosis of breast lesions. Breast surgery frozen section should be used as rarely as possible for diagnostic purposes, despite the generally good diagnostic accuracy. However, it is reasonable to use frozen sections widely until the given preoperative diagnostic tools allow an appropriate preoperative workup, because it is the only way to keep histopathologists trained to interpret frozen sections.

Intra-operative Diagnosis of Breast Lesions by Imprint Cytology and Frozen Section with Histopathological Correlation

INTRODUCTION

The most common malignant tumour among women is breast carcinoma. Early lesions of the breast including carcinoma are potentially curable if treated properly in the era of breast conservative therapy. For this purpose different diagnostic strategies are in practice. Intra operative Imprint Cytology (IC) and Frozen Section (FS) have a role in spite of the intense recognition of aspiration cytology in the following settings: inconclusive cytological/core biopsy findings; for evaluation of lumpectomy margins and intra operative nodal status. Both IC and FS are dependable intra operative diagnostic consultation modalities and provide accurate results in minutes thereby making appropriate therapeutic decision.

AIM

To study the IC and FS features of breast lesions with correlation of final Histopathologic (HP) diagnosis and to determine its diagnostic accuracy.

MATERIALS AND METHODS

This was a descriptive cross-sectional study conducted in the Department of Pathology, JSS Medical College, JSS University, Mysuru over a period of two years (October 2011-September 2013). A total of 62 cases of surgically resected breast specimens were evaluated for features of IC, FS and correlation with HP diagnosis. After describing gross features, representative tissue fragment was taken, three imprint smears were made and same tissue fragment was subjected to FS and later for routine HP processing. Slides prepared by IC, FS were interpreted and later correlated with HP diagnosis. Statistical analysis was done with SPSS for windows (version 16.0) by applying appropriate tests.

RESULTS

Out of 62 cases, 33(53.23%) were malignant and 29(46.77%) were benign. Sensitivity, specificity and accuracy of IC were 100%, 96.43% and 98.36% and for FS were 100%, 96.55% and 98.39% respectively. p-value for both were <0.001 indicating significant correlation with HP study.

CONCLUSION

IC is a simple, accurate, rapid and cost effective diagnostic tool intra operatively where services for FS are not available. It preserves crisp cellular and nuclear detail. FS tissue architecture strongly approximates permanent HP sections but is frequently hampered by freezing artifact. But FS is able to differentiate carcinoma in situ and infiltrative lesions from benign breast lesions. Thus, IC and FS together offer a more reliable diagnosis; hence, it is always useful to prepare both the slides intra operatively. HP study still remains the gold standard in final diagnosis of any breast lesion. In surgical pathology, the correlation of intra operative IC and FS diagnosis with the final HP diagnosis form an essential part of quality assurance activity.

Breast Carcinosarcomas

OBJECTIVE

Carcinosarcomas of the breast are rare and aggressive breast tumors. The optimal treatment strategies and the classification of these difficult to diagnose tumors are not clear in the literature due to their very low incidence. In this study, we aimed to evaluate patients who were operated on for breast carcinosarcoma and discuss the current literature.

MATERIALS AND METHODS

Ten patients who were treated with a diagnosis of breast carcinosarcoma between January 2000 - March 2013 at the Izmir Bozyaka Teaching and Training Hospital General Surgery Clinics were retrospectively analyzed.

RESULTS

The mean age of the patients was 59.7 (±13.4) years. Eight patients underwent modified radical mastectomy, one patient lumpectomy and one patient breast conserving surgery + sentinel lymph node biopsy procedures. The TNM stage of patients were identified as stage 1 in 2 patients, stage 2 in 6 patients, and stage 3 in 2 patients. 60-month disease-free survival rate was 52.5% (±18.6). The overall survival rate was 53.3% (±20.5). Four patients died during follow-up.

CONCLUSION

It is reported that the prognosis of carcinosarcomas are as poor as triple negative epithelial tumors. In contrast to the literature, in our study the disease-free and overall survival rates according to stage were not different from epithelial tumors. In this regard, prospective studies including more patients are required.

Breast Carcinosarcomas

OBJECTIVE

Carcinosarcomas of the breast are rare and aggressive breast tumors. The optimal treatment strategies and the classification of these difficult to diagnose tumors are not clear in the literature due to their very low incidence. In this study, we aimed to evaluate patients who were operated on for breast carcinosarcoma and discuss the current literature.

MATERIALS AND METHODS

Ten patients who were treated with a diagnosis of breast carcinosarcoma between January 2000 - March 2013 at the Izmir Bozyaka Teaching and Training Hospital General Surgery Clinics were retrospectively analyzed.

RESULTS

The mean age of the patients was 59.7 (±13.4) years. Eight patients underwent modified radical mastectomy, one patient lumpectomy and one patient breast conserving surgery + sentinel lymph node biopsy procedures. The TNM stage of patients were identified as stage 1 in 2 patients, stage 2 in 6 patients, and stage 3 in 2 patients. 60-month disease-free survival rate was 52.5% (±18.6). The overall survival rate was 53.3% (±20.5). Four patients died during follow-up.

CONCLUSION

It is reported that the prognosis of carcinosarcomas are as poor as triple negative epithelial tumors. In contrast to the literature, in our study the disease-free and overall survival rates according to stage were not different from epithelial tumors. In this regard, prospective studies including more patients are required.

Diagnosis and Management of Multiple Carcinosarcoma of the Breast in a Young Chinese Patient

BACKGROUND: Carcinosarcoma is an exceptionally rare and poorly differentiated kind of breast neoplasm with only few published reports in the literature. CASE REPORT: We report a case of breast carcinosarcoma in a 26-year-old Chinese female patient, presenting as multiple lumps in a single breast. A nipple-sparing modified radical mastectomy was performed. The patient is now in her 7th postoperative month and disease-free. CONCLUSION: Carcinosarcoma is challenging to diagnose preoperatively, even with core needle biopsy histopathology. Modified radical mastectomy is an efficient and practical operative treatment. Application of adjuvant therapy should be based on the proportion of carcinomatous component of the lesion in pathological test. Careful periodic follow-up after the initial treatment is strongly recommended.

Intraoperative Frozen Section for Margin Assessment in Breast Conserving Surgery

Background and Aims:

When excisional biopsy or lumpectomy is performed without margin assessment in early breast cancer, further surgery are required if positive margins exist. We evaluated the role of the intraoperative frozen section in breast conserving surgery (BCS). Clinicopathologic factors associated with re-excision were searched.

Material and Methods:

190 tumors in 186 patients with early invasive breast cancer treated by BCS. Breast tumor was excised with 2 cm macroscopic margin, and microscopic margins examined by intraoperative frozen section.

Results:

After frozen section, 160 cases had negative margins (no re-excision), but 30 patients (16%) underwent re-excision because of close/positive margins. Negative margins were obtained in 24 patients but six patients underwent mastectomy due to persistent involved margins. Local recurrence was 2.1% and systemic recurrence was 2.6% with mean 62 months follow-up. Tumor type, tumor size, extranodal extension and extensive intraductal component were significant predictors of re-excision by multivariate analysis. Re-excision procedures haven't an impact on local recurrence.

Conclusions:

Intraoperative frozen section is an effective procedure in reducing the need of second operation. We have observed lower recurrence rates than other studies because of our 2 cm macroscopic margin width and > 2 mm microscopic negative margin which obtained by intraoperative frozen section.

Intraoperative frozen section analysis for breast-conserving therapy in 1016 patients with breast cancer

OBJECTIVE

We evaluate the number of surgical two-stage procedures after FSA during breast-conserving therapy (clinical false negative result of FSA) and investigate the influence of microcalcifications, small tumour diameter, neoadjuvant therapy and preoperative biopsy on the clinical false negative rate of FSA.

SUBJECTS

We retrospectively examined 1016 patients after intraoperative FSA during breast-conserving therapy for breast cancer operated between 1995 and 2001 at the Medical University Vienna.

RESULTS

Only 9% of all patients had to undergo a two-stage operation due to a false negative intraoperative FSA result. The annual local recurrence rate was 1.2% in all patients with no difference between one- and two-stage operated patients. In situ and pT1 lesions were similarly distributed between one-stage and two-stage operated patients. The use of neoadjuvant therapy and stereotactic biopsy (reflecting non-palpable lesions and microcalcifications) were significantly predictive for a false negative FSA result. The use of a preoperative core biopsy, however, reduced the necessity of performing a two-stage operation.

CONCLUSION

Our study demonstrates that FSA leads to a low rate of two-stage operations. Small lesions and microcalcifications as well as the occurrence of intraductal cancer cells and neoadjuvant therapy increased while preoperative core biopsy reduced the false negative rate of FSA. Overall local recurrence rates after FSA were acceptable.

Perpendicular inked versus tangential shaved margins in breast-conserving surgery: does the method matter?

BACKGROUND

In breast-conserving surgery (BCS), the method of margin assessment and the definition of a negative margin vary widely. The purpose of this study was to compare the incidence of positive margins and rates of reexcision between two methods of margin assessment at a single institution.

STUDY DESIGN

In July 2004, our protocol for margin evaluation changed from perpendicular inked margins (Group A, n=263) to tangential shaved margins (Group B, n=261). In Group A, margins were classified as positive, close, and negative. Margins designated as "close" were further defined as: < or = 1 mm, < or = 2 mm, and < or =3 mm. In Group B, shaved margins (by definition 2 to 3 mm) were reported as positive or negative.

RESULTS

The rate of reported "positive" margins was significantly higher in Group B: 127 of 261 (49%) versus 42 of 263 (16%), p < 0.001. But when patients with "positive, close, or both" kinds of margins were combined in Group A, there was no significant difference between the two techniques. Although the shaved margin was 2- to 3-mm thick, the rate of reexcision in Group B was significantly higher when compared with that in patients with "positive, close, or both" < or =3 mm margins in Group A (75% versus 52%, p < 0.001). The likelihood of finding residual disease remained the same (27% versus 32%, p=NS).

CONCLUSIONS

The tangential shaved-margin technique results in a higher proportion of reported positive margins and limits the ability of the surgeon to discriminate among patients with close margins, resulting in a higher rate of reexcision. The fact that many, but not all, patients with positive or close margins in both groups underwent reexcision emphasizes the role of surgical judgment in this setting. Longer followup is required to determine equivalency in rates of local recurrence between these two methods of margin assessment.

Frozen section diagnoses of small pulmonary nodules: accuracy and clinical implications

BACKGROUND

Pulmonary nodules are frequently first diagnosed by frozen section, immediately followed by lobectomy or other procedures. The frozen section diagnosis of pulmonary nodules can be difficult, as inflammatory and fibrotic lesions can be confused for malignancy, creating intraoperative dilemmas for pathologists and thoracic surgeons.

METHODS

We reviewed our experience at Cedars-Sinai Medical Center with the frozen section diagnoses of 183 consecutive pulmonary nodules smaller than 1.5 cm in diameter and calculated the sensitivity, specificity, and predictive values of this diagnostic procedure.

RESULTS

One hundred and seventy four nodules were correctly classified by frozen section as neoplastic or nonneoplastic, six lesions were diagnosed equivocally, and two neoplasms were missed owing to sampling errors. The equivocal frozen section diagnoses included two bronchioloalveolar carcinomas (BAC) interpreted as "atypical hyperplasia, favor BAC," two BAC diagnosed as "alveolar hyperplasia," and two carcinoid tumors labeled as "atypical carcinoma" and "spindle cell lesion, carcinoid versus sclerosing hemangioma," respectively. The sensitivities for a diagnosis of neoplasia were 86.9% and 94.1% for nodules smaller than 1.1 cm in diameter and measuring 1.1 to 1.5 cm, respectively. The diagnostic accuracy of frozen sections was significantly better in nodules larger than 1.0 cm in diameter (p = 0.05). There were no false-positive diagnoses of malignancy, resulting in 100% specificity.

CONCLUSIONS

Intraoperative consultation with frozen section is a sensitive and specific procedure for the diagnosis of malignancy from small pulmonary nodules. The distinction between BAC and atypical adenomatous hyperplasia, and of small peripheral carcinoid tumors from other lesions, can be difficult by frozen section. Thoracic surgeons need to become aware of these problems and develop appropriate therapeutic strategies.

[Role of microbiopsy in diagnostic and therapeutic approach of mammary suspect microcalcification]

PURPOSE

To determine the sensibility, the specificity, the positive and negative predictive values of microcalcifications detection by core needle biopsy and intra-operative pathologic examination.

MATERIALS AND METHODS

A hundred and one patients (between 1998 and 1999) were investigated in this retrospective study. The initial presentation was breast microcalcifications without palpable tumour. The mean age of patients was 55 (34-79) years. Mammography was performed in 3 standard projections. All suspect microcalcifications were recommended for surgical excision. In the others cases, 5 core biopsies were taken of the lesion. Needle guidance was accomplished by means of either dedicated stereotaxic device or ultrasound equipment. All biopsies were performed with a biopsy device fitted with 14 G needles. The mean follow-up period was 3 years.

RESULTS

Clinical or surgical follow-up was available in 101 lesions. Only 4 benign lesions did not have surgery. The 97 remaining were subsequently excised. Pathologic study showed cancer in 38 (39%) lesions, carcinoma in-situ in 14 lesions, and benign disease in 45 lesions. There was 1 false-negative biopsy. The specificity and sensitivity of percutaneous biopsy diagnosis were 73,6 and 93,7% respectively. Intra-operative pathologic diagnoses were concordant in 77% of 30 cases. Discordance occurred in 2 cases of atypical hyperplasia with a single false-negative result for a carcinoma that led to an additional surgical procedure. Positive and negative predictive values of intra-operative pathologic diagnosis were 82 and 100% respectively.

CONCLUSION

Needle biopsy findings are accurate and allow definitive therapeutic surgery, including mastectomy.

Surgical margins in patients with early-stage breast cancer treated with breast conservation therapy

BACKGROUND

Patients receiving breast conservation therapy have a lifelong risk of local recurrence. To minimize this risk, surgeons have explored various approaches to examining the surgical margins of the resection specimen. If tumor cells are found at the margin, there is a high probability that residual tumor remains in the surgical cavity. This review examines published reports about standard and innovative approaches to assessing surgical margins, the clinical significance of margin size, and risk factors for positive margins.

METHODS

Published literature abstracted in Medline was reviewed using the Gateway site from the National Library of Medicine.

CONCLUSIONS

It is still not clear whether obtaining a radical margin will decrease the rate of local recurrence after breast conserving surgery. What is clear is that it is absolutely unacceptable to have tumor cells directly at the cut edge of the excised specimen, regardless of the type of post-surgical adjuvant therapy.

Diagnosis of non-palpable breast cancer: a review

The literature on several methods of diagnosing non-palpable breast carcinoma has been reviewed. Skin projection and dye are methods not frequently used. Several aspects of FNA biopsy/cytology, ultrasound-directed methods, frozen section and MRI localization procedures are highlighted and comparisons are made. Much attention is being payed to needle localization breast biopsy and stereotactic core needle breast biopsy. The management of patients with mammographic abnormalities is shifting from needle localization to breast biopsy stereotactic core needle biopsy. Items of comparison between the two mentioned methods are accuracy, indications, complications and costs. The role of the ABBI system in the management of breast cancer has not yet been defined. A cooperative effort between the mammographer, surgeon and pathologist is critical to a successful image-guided breast biopsy programme.

Accuracy of frozen section diagnoses of breast lesions after introduction of a national programme in mammographic screening

AIMS

By introducing mammography screening programmes, the size of the detected breast lesions became smaller and the histopathological interpretation problems greater. The study's aim was to analyse the risks and possible limitations of the frozen section method.

METHODS AND RESULTS

Frozen section consultations of breast lesions (n=559) 2 years before and 6 years after launching a national mammographic screening programme in 1992 were evaluated in regard of the benign/malignant ratio, tumour size, preoperative frozen section results and final permanent section diagnoses. The breast frozen section examinations of 1990 compared with those from 1998 declined from 70.7% (299/423) to 62.2% (260/418) (P < 0.01), the benign/malignant ratio from 1.09 to 0.54 (P < 0.0001), the rate of the conclusive, correct frozen section diagnoses from 96.3% to 91.9% (P < 0.03). The sensitivity dropped from 92.3% to 87.6%, the negative predictive value from 95.7% to 88.3%, whereas the negative likelihood ratio rose from 0.08 to 0.12. The 'small' (< or = 10 mm) invasive breast carcinomas increased from 14.2% to 22.3% (P < 0.01) and the 'in situ' carcinomas from 2.1% to 6.6% (P < 0.05).

CONCLUSIONS

The declining sizes of breast tumours (< or = 10 mm), especially from radiologically detected lesions and sometimes without a macroscopic correlate, create new limitations and changing indications in the histopathological interpretation. Considering the performance of new diagnostic methods (i.e. large core needle biopsies), frozen sections of surgical specimens should not be the primary diagnostic procedure for breast lesions and should be performed only after other preoperative methods have failed.

Palpable breast masses: is there a role for percutaneous imaging-guided core biopsy?

OBJECTIVE

The purpose of this study was to evaluate percutaneous imaging-guided core biopsy in the assessment of selected palpable breast masses.

MATERIALS AND METHODS

Of 1388 consecutive breast lesions that had percutaneous imaging-guided core biopsy, 155 (11%) were palpable. Palpable masses referred for percutaneous imaging-guided core biopsy included lesions that were small, deep, mobile, vaguely palpable, or multiple. Biopsy guidance was sonography in 140 lesions (90%) and stereotaxis in 15 (10%). Surgical correlation or minimum of 2 years follow-up is available in 115 palpable masses in 107 women. Medical records, imaging studies, and histologic findings were reviewed.

RESULTS

Of 115 palpable breast masses, 98 (85%) were referred by surgeons to the radiology department for percutaneous imaging-guided core biopsy and 88 (77%) had percutaneous imaging-guided core biopsy on the day of initial evaluation at our institution. Percutaneous imaging-guided core biopsy spared additional diagnostic tissue sampling in 79 (74%) of 107 women, including 57 women with carcinoma and 22 women with benign findings. Percutaneous imaging-guided core biopsy did not spare additional tissue sampling in 28 women (26%), including 15 women in whom surgical biopsy was recommended on the basis of percutaneous biopsy findings and 13 women with benign (n = 7) or malignant (n = 6) percutaneous biopsy findings who chose to undergo diagnostic surgical biopsy.

CONCLUSION

Percutaneous imaging-guided core biopsy is useful in the evaluation of palpable breast masses that are small, deep, mobile, vaguely palpable, or multiple. In this study, percutaneous imaging-guided core biopsy spared additional diagnostic tissue sampling in 74% women with palpable breast masses.

Ultrasound-guided fine-needle aspiration (FNA) of nonpalpable breast lesions: a review of 1885 FNA cases using the National Cancer Institute-supported recommendations on the uniform approach to breast FNA

BACKGROUND

A probabilistic approach to the classification of fine-needle aspirates (FNAs) of the breast recently was recommended and received endorsement from the National Cancer Institute (NCI). In this system, FNAs are classified as benign, indeterminate/atypical, suspicious/probably malignant, and malignant, but to the authors' knowledge the use of these diagnostic categories has not been evaluated on a large scale. Furthermore, this classification scheme has not been applied to FNAs of nonpalpable lesions of the breast obtained under imaging guidance. Thus, the current study focused on whether the diagnostic categories could be applied usefully to ultrasound-guided FNAs (US-FNAs) of nonpalpable breast lesions.

METHODS

Between 1988-1996, 1885 US-FNAs were performed on 1639 patients. The original FNA diagnoses were reclassified into the NCI-supported recommendations for diagnostic categories of breast FNAs. The cytologic findings were correlated with the tissue specimens, which were available in 851 cases, or with clinical follow-up of a minimum of 2 years in 127 of the 274 patients with benign solid lesions.

RESULTS

The 1885 cases were categorized as follows: 1057 (56.1%) as benign, 86 (4.6%) as atypical, 79 (4.2%) as probably malignant, 502 (26.6%) as malignant, and 161 (8.5%) as unsatisfactory (defined as < 6 epithelial cell groups on all slides). The benign US-FNAs included 480 (45.4%) cysts and 577 (54.6%) solid lesions. Combined clinical and surgical follow-up showed that the frequency of malignancy was 3.7% in US-FNAs classified as benign, 52.9% in those designated as atypical, 75.8% in those designated as suspicious, and 98.9% in those classified as malignant. Based on combined histologic and clinical follow-up, a sensitivity of 97.1% and specificity of 99.1% were found for US-FNAs when definitive benign and malignant diagnoses were considered. A false-negative rate of 3.7% was attributed to sampling error. A false-positive rate of 0.68% was secondary to interpretative error of proliferative lesions.

CONCLUSIONS

Application of the NCI-supported diagnostic categories to US-FNA of nonpalpable breast lesions is useful in stratifying aspirates based on the likelihood of underlying malignancy. The subcategories of US-FNAs diagnosed as atypical have similar probabilities of malignancy; this justifies their being grouped as a single category wherein tissue biopsy would be required to exclude carcinoma. Benign and inadequate FNA diagnoses must be correlated with the clinical and imaging findings and in noncorrelative cases the patient should undergo biopsy. US-FNA is a sensitive and specific means with which to diagnose nonpalpable breast lesions.

Telepathology diagnosis by means of digital still images: an international validation study

Telepathology affords the means to provide pathological diagnosis and consultation to remote sites. However, before telepathology can become an acceptable medical tool, it will be vital to determine the diagnostic accuracy of this technology. We report the results of a single-blind study of the accuracy of diagnosis performed using computerized still images obtained from a telepathology workstation used in a French telepathology network. Four pathologists, each working alone, reviewed a total of 200 cases of routine surgical pathology (50 cases each), and performed diagnosis based on both computer CD-ROM still images (CD) and conventional glass slides (GS). Concordance between GS and CD diagnosis, as well as accuracy, were determined. Other factors related to performance were also measured, including diagnostic certainty, reasons for uncertainty, and causes of diagnostic error. Overall, there was good agreement between CS and CD diagnosis. There was 87.5% concordance between CS and CD diagnosis, and comparison to consensus (correct) diagnosis showed accuracy of 95.5% and 88.5% for GS and CD diagnosis, respectively. Marked variability in accuracy of CD diagnosis was observed among the four pathologists, and issues related to image selection and/or quality appeared responsible for 60% of the diagnostic errors. The lack of sufficient images and clinical information were frequently cited as reasons for diagnostic uncertainty, as well as feelings of insufficient expertise. It is likely that the opportunity for interaction with the referring pathologist and the use of subspecialty consultants would likely improve the performance of telepathology.