The significance of the diagnosis of atypia in breast fine-needle aspiration

Accuracy of the International Academy of Cytology Yokohama system of breast cytology reporting for fine needle aspiration biopsy of the breast in a dedicated breast care setting

BACKGROUND

The International Academy of Cytology (IAC) Yokohama system is a recently proposed system for reporting breast cytology by fine needle aspiration biopsies (FNAB). Multiple studies are needed to confirm the risk of malignancy (ROM) of the various reporting categories of this system. The present article studies the accuracy of the IAC Yokohama system in our center.

METHODS

Over a period of 1 year (September 2018-August 2019), all cases of breast masses assessed by FNAB and histological correlation were studied retrospectively. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) and overall accuracy of the IAC Yokohama system for diagnosing malignancy were assessed. The rates of malignancy (ROM) of each diagnostic category were also estimated.

RESULTS

Three hundred and twenty-one FNABs had cyto-histological correlation. The percent sensitivity (with 95% Confidence Intervals) when the atypical, suspicious of malignancy and the malignant categories were regarded as positive for malignancy were 98.2% [95.5%, 99.5%], 96.0% [92.5%, 98.2%], and 86.7% [81.5%, 90.8%] respectively. The percent specificity (with 95% Confidence intervals) for the same categories in the same order were 59.5% [47.4%, 70.7%], 91.9% [83.2%, 97.0%], and 100% [95.1%, 100%] respectively. The area under curve (AUC) for diagnosing malignancy was 0.981[0.963, 0.993]. The ROM for the benign, atypical, suspicious of malignancy and malignant category were 8.3% [2.3%, 20.0%], 17.2% [5.8%, 35.8%], 77.8% [57.7%, 91.4%], and 100% [98.1%, 100%] respectively.

CONCLUSION

The IAC Yokohama system is suitable for accurately reporting breast lesions on FNAB.

Cytological Scoring of Breast Lesions and Comparison with Histopathological Findings

Context

Cytological assessment using various morphological parameters helps segregate breast lesions in fine-needle aspiration cytology (FNAC) into different categories. The prognosis and the line of management of each category differ accordingly.

Aims

This study aims at assessing the validity of Modified Masood's Scoring Index (MMSI) by the evaluation of cytomorphological features of various breast lesions compared with histopathological findings.

Settings and Design

This is a cross-sectional study done in 65 female patients with palpable or nonpalpable breast lesions, undergoing FNAC and biopsy over a period of 18 months from December 1, 2012, to May 31, 2014.

Materials and Methods

MMSI categorizes breast lesions, based on six cytological parameters into different categories such as nonproliferative breast disease (NPBD), proliferative breast disease (PBD) without atypia, PBD with atypia, and malignancy. The findings are compared with gold standard histopathological diagnosis.

Statistical Analysis Used

Percentage of agreement, Kappa statistics, and Chi-square test.

Results

Of the total 65 cases, all cases in MMSI category I and IV showed good histopathological correlation. The agreement between MMSI and histopathology was 93.8% which is more when compared with 72.3% agreement between cytology without scoring and histopathology. MMSI has increased the diagnostic accuracy of FNAC to 93.8% from 80%.

Conclusion

The scoring system is easily reproducible, simple, and reliable. MMSI proved good histopathological correlation in category I and IV. This scoring technique has clearly demarcated those cases requiring surgical management. It is applicable for palpable and nonpalpable cases.

Fine needle aspiration cytology of atypical (C3) and suspicious (C4) categories in the breast and its histopathologic correlation

BACKGROUND

In 1996, National Cancer Institute (NCI) proposed five categories for the diagnosis of breast cytology in order to bring a degree of uniformity to the diagnostic reporting. Of these, categories 3 and 4 were sparsely studied.

AIMS

The present study was undertaken for the evaluation of the fine needle aspiration cytology (FNAC) categories of C3 and C4 in the breast lump and its histopathological correlation.

MATERIALS AND METHODS

In the retrospective study, a total number of 728 FNACs were categorized according to the NCI; of these, 28 cases of category C3 and 65 cases of category C4 were compared with histopathological diagnoses.

RESULTS

On histopathological examination of category C3, 18 (64.3%) cases showed benign lesions and 10 (35.7%) cases showed malignancy and among the C4 category, benign lesions found in nine (13.8%) and malignancy found in 56 (86.2%) cases. There was a significant statistical difference between the number of benign and malignant diagnoses for cytological categories of C3 (64.3%) and C4 (86.2%) (P < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of C4 category in the diagnoses of malignancy were 84.8%, 66.7%, 86.2%, and 64.3%, respectively.

CONCLUSION

FNAC of the breasts is a simple, cost-effective, accurate, quick, and relatively less painful procedure, and it continues to play an integral part in the management of breast lesions. Our study concluded that there was a statistically significant difference between the number of benign and malignant diagnoses for categories of C3 and C4.

What should not be reported as atypia in urine cytology

The term "atypia," although not well characterized, is widely used in diagnostic surgical and cytopathology. Because there are no guidelines regarding when to use this term, in the majority of cases, it is used as a "wastebasket." This definitely applies to urine cytology, where the reported rate of atypia ranges from 1.9% to 23%. This review lists a number of cytomorphologic findings in urine cytology that are associated with known and specific causes. Urine specimens in which the morphologic changes can be attributed to particular etiologic factors should no longer be classified as "atypical." These include urine specimens showing reactive umbrella cells or seminal vesicle cells, reactive changes due to stones, cytologic changes characteristic of infectious processes or therapy effect, instrumented urines with pseudopapillary clusters, and urinary diversion specimens.

The microscopic complexities of C3 in breast cytology

BACKGROUND

Fine-needle aspiration (FNA) of difficult breast lesions often results in an atypical (C3) report. The assortment of outcomes generated by C3 reports varies widely, and this has given rise to different clinical management pathways.

OBJECTIVE

To identify and objectively assess microscopic features associated with atypical/C3 breast FNA cases.

MATERIALS AND METHODS

A total of 230 atypical breast FNAs were subjected to a blind microscopic rescreen using a range of robust qualitative and quantitative cytological criteria including cellularity, architectural qualities, cytomorphology and background features. A logistic regression with a receiver operating characteristic (ROC) curve and the resultant forward stepwise analysis were conducted to assess the results. This statistical testing was measured against malignant, benign proliferative and benign non-proliferative outcomes.

RESULTS

The malignant and benign proliferative outcomes showed a mixture of opposing protective and predictive individual cytological criteria. The stepwise analysis produced models demonstrating the best combination of individual cytological criteria for malignancy, proliferative and benign non-proliferative entities. In the malignancy model, discohesion, nuclear crowding within sheets, diminished numbers of bare bipolar nuclei and myoepithelial cells, the presence of tubules or necrosis and the absence of a cystic background were important features. The benign proliferative model suggested the same criteria but with the opposite implication and with the addition of several others, such as the presence of apocrine metaplasia, retained polarity and a speckled or coarse chromatin pattern. Age was a significant factor in malignant and proliferative outcomes. The benign non-proliferative stepwise analysis produced a model with fewer criteria (complex sheets, bare bipolar nuclei and a cystic background) limiting clinical application.

CONCLUSION

Atypical/C3 breast cytology remains a legitimate reporting category. However, it is associated with a number of different histological outcomes. The incidence of the C3 category can be significantly reduced by controlling extrinsic factors and understanding the associated microscopic features.

Histopathological correlation of atypical (c3) and suspicious (c4) categories in fine needle aspiration cytology of the breast

Introduction. According to the National Cancer Institute (NCI) guidelines in 1996, breast lesions are categorized as C1 to C5 on fine needle aspiration (FNA) cytology. Very few studies are available in the English literature analyzing histopathology outcome of C3 (atypical, probably benign) and C4 (suspicious, probably malignant) lesions. Our study aims to correlate FNA cytology of breast lump diagnosed as C3 and C4 lesion with histopathological examination. Methods. During a period of 2 years, 59 cases of C3 and 26 cases of C4 were retrieved from total 1093 cases of breast FNA. All the cases were reviewed by two cytopathologists independently. The final 24 cases of C3 and 16 cases of C4 categories were correlated with histopathological diagnosis. Result. Among C3 category, 37.5% revealed malignant findings, whereas of C4 category, 87.5% were malignant on histopathology. This difference was statistically significant (P = 0.0017). Sensitivity, specificity, positive predictive values, and negative predictive value of C4 category in diagnosing breast malignancy were 60.8%, 88.2%, 87.5%, and 62.5%, respectively. Conclusion. Although FNAC is simple, safe, cost-effective and accurate method for diagnosis of breast masses, one must be aware of its limitations particularly in C3 and C4 categories. Also, since both these categories carry different probabilities of malignancy and thus different management, we therefore, support maintaining C3 and C4 categories.

The true nature of atypical breast cytology

BACKGROUND

Atypical breast cytology is a poorly understood heterogeneous category with limited clinical utility but significant implications for patient management.

OBJECTIVE

To provide an insight into the true nature of atypical breast cytology in screening-detected (asymptomatic) and symptomatic settings, and find strategies for reducing the use of this diagnostic category.

MATERIALS AND METHODS

A total of 6,415 breast cytology samples were processed between January 2004 and December 2008. An atypical cytological diagnosis was rendered in 256 (4%) of the cases. A blind microscopic review of the atypical cases was conducted and results were correlated with subsequent histological and/or clinical outcomes.

RESULTS

Follow-up information by histology was available in 85.5%, by repeat fine-needle aspiration (FNA) in 3.5% and by imaging or clinical follow-up in 10.2% of the cases. Two patients (0.8%) were lost to follow-up. Of the 254 cases with follow-up, 62.6% were benign and 37.4% were malignant. The benign to malignant ratios were 1:1 and 2:1 in the screening and symptomatic groups, respectively. The atypical category in the screening population mostly yielded fat necrosis, complex sclerosing lesions and low- to intermediate-grade carcinoma on follow-up. The main outcomes in the symptomatic group were papilloma, fibroadenoma, ductal carcinoma in situ and lobular carcinoma. Preanalytical (suboptimal samples) factors were encountered in 34.8% and interpretative factors in 65.2% of the cases. Uncertainty about cellular morphology was attributed to such a diagnosis in 38 (14.8%) of the cases, architectural complexity in 137 (53.5%) and morphology and architecture in 70 (27.3%); 4.3% of cases were considered nondiagnostic.

CONCLUSION

The atypical category is a necessary diagnosis but of limited use from a patient management perspective. Some preanalytical factors such as poor sample quality can be minimized by the involvement of cytopathologists in the FNA procedure. The use of the atypical category is partly dependent on the experience and confidence of the reporting pathologist. Assigning a case to this category is also likely to be unduly influenced by clinical or radiological findings. Our study indicates that the use of the atypical category can be reduced by up to 40% by appreciating these contributing factors. The practical utilization of the atypical category in breast cytology remains subjective and further study is required to identify useful objective criteria.

Fine-needle aspiration of gray zone lesions of the breast: fibroadenoma versus ductal carcinoma

While breast lesions have characteristic cytological features, some lesions, particularly adenocarcinoma and fibroadenoma, may present with overlapping features causing erroneous diagnoses. The current study aimed to define significant cytomorphologic features predictive of fibroadenoma and adenocarcinoma, respectively. Further, we intended to evaluate the predictive characteristics for differentiation between gray zone lesions and to identify root causes contributing to misdiagnoses. First, direct smears prepared from 14 histology-confirmed fibroadenomas and 14 adenocarcinomas were reviewed and characteristics of commonly encountered morphologic features were assessed. We then retrospectively and blindly reviewed nine cytohistologic discrepant cases using the significant characteristic as a guideline, in order to assess whether these discrepant cases could be correctly categorized. Morphologic characteristics predictive of fibroadenoma included moderate cellularity, large, folded cellular sheets/aggregates, staghorn projections, smooth and round borders, monolayers, honeycomb arrangement, smaller nuclear size, and background bipolar cells. Predictive characteristics of adenocarcinoma included high cellularity, loose cohesive sheets/aggregates, pointed projections, irregular borders, larger nuclear size, irregular nuclear membrane, prominent nucleoli, and single atypical epithelial cells. Retrospective, blind review correctly re-classified seven out of nine cytohistologic discrepant cases, including five false negative cases and two false positive cases. Root causes contributing to the misdiagnoses were large branching sheets of carcinoma mimicking folded sheets of fibroadenoma; fibroblasts mimicking myoepithelial cells; apocrine cells mimicking carcinoma cells; and not recognizing the loose myxoid matrix presenting as soap bubbles in fibroadenoma. In conclusion, this study identified significant characteristics that can assist in achieving accurate diagnosis in a subpopulation of breast aspirates that present with overlapping features.

Positive predictive value of the breast FNAB diagnoses of epithelial hyperplasia with atypia, papilloma, and radial scar

Proliferative breast lesions are a spectrum of lesions that have overlapping cytological features and are difficult to subclassify in fine-needle aspiration biopsies (FNABs). This study of breast FNABs from the period of 1997-2001 aimed to correlate the cytological diagnoses of epithelial hyperplasia with atypia (EHA), papilloma (PAP), and radial scar/complexing sclerosing lesions with relevant histological follow-up, and to assess the positive predictive value (PPV) of the cytological diagnosis. The PPV for the three categories were found to be 0.16, 0.74, and 0.63 respectively. The low value observed in the cytological category of EHA was due to the heterogeneous nature of the group, which makes it difficult to correlate cytological appearances with the varying histological lesions. However, it was found that 70% of these EHA cases had benign histological diagnoses, matching the expected outcome. The PPV of 0.74 for the cytological diagnosis of PAP of the breast compares favorably to similar published studies, and we suggest that the specific diagnosis of PAP can be made reliably using cytological criteria.

Breast Fine Needle Aspiration Biopsy: Prevailing Recommendations and Contemporary Practices

In 1996, a National Cancer Institute conference was held in Bethesda,Maryland to define parameters for the practice of breast fine needle aspiration (BFNA). Representatives of the American Society of Cytopathology, Papanicolaou Society of Cytopathology, American College of Radiology, American College of Obstetricians & Gynecologists, Society of Surgical Oncology, American Academy of Family Physicians, College of American Pathologists, National Consortium of Breast Centers, International Academy of Cytology, American Society of Clinical Pathologists, American Cancer Society, American College of Surgeons, and American Society for Cytotechnology developed and reviewed recommendations. These guidelines were referred to as "The Uniform Approach to Breast Fine Needle Aspiration Biopsy." This article reviews these recommendations and the contemporary evolution of the practice of BFNA since their original publication.

Cytomorphology of Common Malignant Tumors of the Breast

A definitive cytologic diagnosis of breast cancer is usually possible when using the six major criteria of malignancy (cellularity, dyshesion, monomorphism, anisonucleosis, irregular nuclear membranes, prominent nucleoli) as part of the triple test. Carcinomas of special type have unique clinical and cytologic features that pathologists need to consider, because these may confuse interpretation. Complete subtyping of carcinomas may not always be possible by fine needle aspiration. Diagnostic accuracy for breast carcinoma is excellent. False-negative diagnoses are infrequent and chiefly due to sampling issues. False-positive diagnoses are extremely rare. Uniform report terminology should be used to ensure that diagnostic information is conveyed appropriately and consistently to guide the next diagnostic or treatment step.