An audit of "equivocal" (C3) and "suspicious" (C4) categories in fine needle aspiration cytology of the breast

Diagnostic Utility of Fine-Needle Aspiration Cytology (FNAC) and Frozen Section Against Histopathology in Evaluating Benign and Malignant Breast Lesions

INTRODUCTION

Breast lesions, particularly lumps, pose concerns for females, varying between benign and malignant conditions. Accurate differentiation solely through clinical assessment is challenging, necessitating a definitive diagnostic strategy. Fine-needle aspiration cytology (FNAC) is integral in the "triple approach" to breast evaluation, offering simplicity, reliability, and cost-effectiveness. However, FNAC has limitations, occasionally failing to yield definitive diagnoses due to inherent constraints. Contrarily, frozen-section analysis, a long-standing intraoperative diagnostic method, plays a crucial role in swift diagnosis during surgeries. Despite technological advancements, frozen sections serve specific diagnostic purposes, confirming carcinoma when FNAC is inconclusive and evaluating resected margins. However, freezing artifacts may affect tissue assessment, emphasizing the continued reliance on histopathology for guiding treatment decisions.

OBJECTIVES

This study was conducted at KVG Medical College and Hospital, Sullia, Karnataka, India. It aimed to analyze the morphological characteristics of benign and malignant breast lesions using FNAC, frozen section, and histopathology and evaluate the sensitivity, specificity, and predictive values of FNAC and frozen section against histopathology as the reference standard.

METHODS

A cross-sectional investigation was carried out at a tertiary care hospital's Department of Pathology, on 60 female patients who presented with palpable breast masses over a span of two and a half years. FNAC was conducted, and the observations were classified into five categories as per the International Academy of Cytology guidelines. In addition, intraoperative frozen-section analysis was undertaken. A comparative analysis was conducted between the FNAC and intraoperative frozen-section findings, juxtaposed with the subsequent histopathological diagnoses.

RESULTS

FNAC revealed 51.7% malignant, 45% benign, and 3.3% inadequate cases; the frozen-section analysis indicated 51.6% malignant, 45% benign, and 3.3% deferred cases; histopathology showed 53.3% malignant, 45% benign, and 1.6% borderline cases. FNAC demonstrated 93.9% sensitivity, 100% specificity, 100% positive predictive value (PPV), 93.1% negative predictive value (NPV), and 96.7% accuracy. The frozen-section analysis exhibited 96.9% sensitivity, 100% specificity, 100% PPV, 96.4% NPV, and 98.3% accuracy.

CONCLUSION

Intraoperative frozen-section analysis displays superior diagnostic utility compared to preoperative FNAC. However, histopathology remains the definitive gold standard. Integrating all three diagnostic modalities is crucial for precise diagnosis and effective patient management.

Correlation Between Ultrasound BI-RADS 4 Breast Lesions and Fine Needle Cytology Categories in a Sample of Iraqi Female Patients

Background: Breast cancer is the most common malignancy in female and the most registered cause of women’s mortality worldwide. BI-RADS 4 breast lesions are associated with an exceptionally high rate of benign breast pathology and breast cancer, so BI-RADS 4 is subdivided into 4A, 4B and 4C to standardize the risk estimation of breast lesions.

The aim of the study: to evaluate the correlation between BI-RADS 4 subdivisions 4A, 4B & 4C and the categories of reporting FNA cytology results.

Patients and Methods: A case series study was conducted in the Oncology Teaching Hospital in Baghdad from September 2018 to September 2019. Included patients had suspicious breast findings and given BI-RADS 4 (4A, 4B, or 4C) in the radiological report accordingly. Fine needle aspiration was performed under the ultrasound guide and the results were classified into five categories. The biopsy was performed for suspicious, malignant or equivocal FNA findings.

Results: This study included 158 women with BIRADS 4 breast lesions with the mean age of (44.6 years); There was a highly significant association between BI-RADS 4 breast lesion and FNA results (p<0.001); 51.9% of BI-RADS IV-C had C5 FNA results. There was a highly significant association between BI-RADS 4 lesion and the final diagnosis (p<0.001); 41.2% of BI-RADS 4 B had a malignant breast lesion, while 37.3% of BIRADS 4 C had a malignant lesion.

Conclusion: A clear relationship was observed between BI-RADS 4 subcategories and the fine needle aspiration cytology subgroups. BI-RADS 4-B is helpful in the discrimination between benign and malignant breast lesions; furthermore BI-RADS 4C has more acceptable validity in the diagnosis of breast malignancy. Therefore, BI-RADS subcategories are encouraged to be included and mentioned in the ultrasound report for more accurate estimation of the lesion nature.

Fibroepithelial tumours of the breast-a review

Fibroepithelial tumours of the breast are biphasic neoplasms composed of both epithelial and stromal elements, including the common fibroadenoma and the infrequent phyllodes tumour. The admixture of epithelium and stroma in the fibroadenoma shows intra- and pericanalicular patterns, and may display a variety of histological changes. Fibroadenoma variants include the cellular, juvenile, myxoid and complex forms. The cellular fibroadenoma may be difficult to distinguish from the benign phyllodes tumour. Stromal mitotic activity can be increased in fibroadenomas in the young and pregnant patients. Phyllodes tumours, neoplasms with the potential for recurrence, show an exaggerated intracanalicular growth pattern with broad stromal fronded architecture and stromal hypercellularity. They are graded into benign, borderline and malignant forms based on histological assessment of stromal features of hypercellularity, atypia, mitotic activity, overgrowth and the nature of the tumour borders. Classification of phyllodes tumours is imperfect, compounded by tumour heterogeneity with overlapping microscopic features among the different grades, especially in the borderline category. Malignant phyllodes tumours can metastasise and cause death. Determining which phyllodes tumours may behave aggressively has been difficult. The discovery of MED12 mutations in the pathogenesis of fibroepithelial tumours, together with other gene abnormalities in the progression pathway, has allowed refinements in diagnosis and prognosis.

The International Academy of Cytology Yokohama System for Reporting Breast Cytopathology showed improved diagnostic accuracy

BACKGROUND

The aim of the International Academy of Cytology Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology is to improve cytology practice. This study assessed cytologic diagnoses made with the system and its efficacy when it was applied by pathologists with different levels of experience.

METHODS

In all, 1080 cases of breast fine-needle aspiration biopsy (FNAB) over a period of 16 years were reviewed and reclassified with the system. The category distribution and the diagnostic performance were compared with the original diagnoses. The concordance rates for diagnoses from pathologists with different levels of experience were also determined.

RESULTS

The distribution of cytologic diagnoses made with the system was as follows: 11.7% were insufficient, 56.6% were benign, 20.1% were atypical, 6.1% were suspicious for malignancy, and 5.6% were malignant. The rates for the insufficient and atypical categories were lower than the original diagnosis rates (13.1% and 23.8%, respectively). Overall, 120 cases (11.1%) were recategorized. Among those recategorized as benign, suspicious, or malignant with follow-up data, 96.7% were correctly reclassified. A significant improvement in diagnostic performance was found with the system (P < .001). Such improvement was also seen in problematic breast lesions, including fibroepithelial lesions, papillary lesions, and low-grade carcinomas. Pathologists with intermediate experience showed a higher concordance with an expert pathologist in the diagnoses than those with short experience (κ, 0.838 vs 0.634).

CONCLUSIONS

The system effectively categorized the diagnoses, and the diagnostic performance of FNAB reporting was improved. The structured reporting also enhanced the reproducibility of reporting by pathologists with intermediate experience and, to some extent, those with short experience.

International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy Cytopathology: A Review of Predictive Values and Risks of Malignancy

OBJECTIVE

We aimed to assess the risk of malignancy (ROM) and predictive values in prior breast cytology studies as a basis for the new International Academy of Cytology (IAC) Yokohama system for reporting breast fine-needle aspiration biopsy (FNAB) cytology, which classifies cytologic diagnoses into 5 categories: (1) insufficient material, (2) benign, (3) atypical, (4) suspicious of malignancy, and (5) malignant.

STUDY DESIGN

Publications between January 1, 1997, and December 31, 2017, that studied the performance characteristics of FNAB from palpable and nonpalpable breast masses were identified through the PubMed database. Data for number of total cases and cases within each diagnostic category, if available, were collected. Performance characteristics, including absolute sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and ROM for each category were recorded or, when possible, calculated.

RESULTS

The literature review resulted in a case cohort of 33,341 breast FNABs, drawn from 27 studies. Pooling these cases together, the ROM for insufficient material, benign, atypical, suspicious, and malignant were 30.3, 4.7, 51.5, 85.4, and 98.7%, respectively. The complete sensitivity and specificity were 96.3 and 98.8%, correspondingly. The PPV and NPV were 98.7 and 95.3%, correspondingly. The false-negative and false-positive rates were 3.7 and 1.0%, respectively.

CONCLUSIONS

This meta-analysis demonstrates that the diagnostic categories of the new IAC Yokohama System each carry an implied ROM, which increases from the benign to malignant categories. This study also shows the high sensitivity and specificity of FNAB for breast lesions.

The International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy Cytopathology

The International Academy of Cytology (IAC) gathered together a group of cytopathologists expert in breast cytology who, working with clinicians expert in breast diagnostics and management, have developed the IAC Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy (FNAB) Cytology. The project was initiated with the first cytopathology group meeting in Yokohama at the 2016 International Congress of Cytology. This IAC Yokohama System defines five categories for reporting breast cytology, each with a clear descriptive term for the category, a definition, a risk of malignancy (ROM) and a suggested management algorithm. The key diagnostic cytopathology features of each of the lesions within each category will be presented more fully in a subsequent atlas. The System emphasizes that the crucial requirements for diagnostic breast FNAB cytology are a high standard for the performance of the FNAB and for the making of direct smears, and well-trained experienced cytopathologists to interpret the material. The performance indicators of breast FNAB, including specificity and sensitivity, negative predictive value, positive predictive value and ROM stated in this article have been derived from the recent literature. The current practice of breast FNAB has evolved with the increasing use of ultrasound guidance and rapid on-site evaluation. Two recent publications have shown a range of ROM for the insufficient/inadequate category of 2.6-4.8%, benign 1.4-2.3%, atypical 13-15.7%, suspicious of malignancy 84.6-97.1%, and malignant 99.0-100%. The management algorithm in the System provides options because there are variations in the management of breast lesions using FNAB and core-needle biopsy in those countries utilizing the "triple test" of clinical, imaging, and FNAB assessment, and also variations in the availability of CNB and imaging in low- and middle-income countries. The System will stimulate further discussion and research, particularly in the cytological diagnostic features of specific lesions within each category and in management recommendations. This will lead to continuing improvements in the care of patients with breast lesions and possible modifications to the IAC Yokohama System.

Micronucleus Study on Breast Cytology Aspirate Smears and its Diagnostic Utility

Background:

Micronucleus is a small fragment of nucleus present in the cells which have undergone chromosomal damage. It is used as a biomarker of genomic damage.

Aims:

We aim to study the presence of micronucleus on breast cytology smears and the use of scoring the micronucleus as an additional criteria for the classification of breast lesions with emphasis on borderline gray zone categories.

Settings and Design:

This is a cross-sectional retrospective descriptive study.

Materials and Methods:

Retrospective analysis of breast cytology smears received over a period of 2 years formed the basis of the study. Micronucleus scoring was done by counting the number of micronuclei in 1000 epithelial cells under oil immersion and compared in the benign, adenosis, usual/atypical ductal hyperplasia, and the three grades of infiltrating ductal carcinomas.

Statistical Analysis:

Descriptive analyses and one-way analysis of variance was used for statistical analysis.

Results:

Of the 243 cases, the average statistically significant (P < 0.05) micronuclei scores of the benign (190), adenosis (7), usual (11)/atypical (5) hyperplasia, grade 1, 2, and 3 carcinomas (30) were 0.5, 2, 2.9, 6.6, 13.2, 20.6, and 27.5, respectively (the corresponding median scores were 0.5, 2, 3, 6, and 20, respectively). Micronucleus score of ≤1 had a high sensitivity (100%) and specificity (99%) in confirmation of benign cases. Micronucleus score of ≥5 and <10 had a moderate sensitivity (60%) but a high specificity of 99% in detecting atypical ductal hyperplasia. Micronucleus score of ≥10 had a high sensitivity (96%) and specificity (99%) of detecting carcinomas.

Conclusion:

Micronucleus scores showed a gradual increase across the categories proving the gradual occurrence of genomic damage. Micronucleus scoring serves as an additional criterion for the diagnosis of breast lesions.

Atypical aspirates of the breast: a dilemma in current cytology practice

Aims

The probabilistic approach is widely adopted for breast fine needle aspiration cytology. However, a definite cytological diagnosis is not always possible for C3 (atypia) cases, which poses a management dilemma as this represents a mixed category of benign and malignant cases. It would be beneficial to be able to predict malignancy based on specific cytological features in C3 aspirates.

Methods

A comprehensive panel of cytological features (including quantitative, cytomorphological and background features) in a large cohort of C3 breast aspirates with subsequent histological excisions was evaluated to identify relevant morphological criteria predicting the risk of subsequent malignancy.

Results

A total of 229 C3 specimens with histological follow-up were included. Malignant outcome was found in 30.1% of specimens and the majority were invasive cancers. Features that showed a significant association with malignant outcome included older age (p=0.001), lower percentage of epithelial cell clusters and high percentage of single cells (p=0.002), cribriform architecture in cell clusters (p=0.034), presence of intracellular mucin (p=0.027), increased cell clusters without myoepithelial cells (p=0.048), diminished fibromyxoid stromal fragments (p=0.001), reduced bipolar nuclei (p=0.021) and the presence of necrosis (p=0.023). Except for the percentages of single cells and cell clusters without myoepithelial cells, all other features were shown to be independent risk predictors in multivariate analysis.

Conclusions

C3 aspirates were associated with a significant probability of histological malignancy. Certain quantitative, cytomorphological and background features were potentially helpful in predicting the risk of a malignant outcome. The prediction could be clinically useful in the management of C3 cases.

Fine-needle aspiration and core biopsy in the diagnosis of breast lesions: A comparison and review of the literature

In recent times, the diagnosis of breast lesions has mostly become dependent on core needle biopsies (CNBs) with a gradual reduction in the rate of performing fine-needle aspiration cytology (FNAC). Both the procedures have their pros and cons and outsmart each other taking into account different parameters. Both the methods are found to be fraught with loopholes, taking into account different performance indices, diagnostic accuracy and concordance, patient benefit, and cost-effectiveness. Unlike the popular belief of an absolute superiority of CNB over FNAC, the literature review does not reveal a very distinct demarcation in many aspects. We recommend judicious use of these diagnostic modalities in resource-limited settings and screening programs taking into account parameters such as palpability and availability of an experienced cytopathologist.

Modified Core Wash Cytology: A reliable same day biopsy result for breast clinics

BACKGROUND

Fine Needle Aspiration Biopsy (FNAB), Core Needle biopsy (CNB) and hybrid techniques including Core Wash Cytology (CWC) are available for same-day diagnosis in breast lesions. In CWC a washing of the biopsy core is processed for a provisional cytological diagnosis, after which the core is processed like a regular CNB. This study focuses on the reliability of CWC in daily practice.

METHODS

All consecutive CWC procedures performed in a referral breast centre between May 2009 and May 2012 were reviewed, correlating CWC results with the CNB result, definitive diagnosis after surgical resection and/or follow-up. Symptomatic as well as screen-detected lesions, undergoing CNB were included.

RESULTS

1253 CWC procedures were performed. Definitive histology showed 849 (68%) malignant and 404 (32%) benign lesions. 80% of CWC procedures yielded a conclusive diagnosis: this percentage was higher amongst malignant lesions and lower for benign lesions: 89% and 62% respectively. Sensitivity and specificity of a conclusive CWC result were respectively 98.3% and 90.4%. The eventual incidence of malignancy in the cytological 'atypical' group (5%) was similar to the cytological 'benign' group (6%).

CONCLUSION

CWC can be used to make a reliable provisional diagnosis of breast lesions within the hour. The high probability of conclusive results in malignant lesions makes CWC well suited for high risk populations.

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.

Is ultrasound-guided fine-needle aspiration cytology of adequate value in detecting breast cancer patients with three or more positive axillary lymph nodes?

This study evaluated the accuracy of ultrasound-guided fine-needle aspiration cytology of the sonographically most suspicious axillary lymph node (US/FNAC) to select early breast cancer patients with three or more tumour-positive axillary lymph nodes. Between 2004 and 2014, a total of 2130 patients with histologically proven early breast cancer were evaluated and treated in the Noordwest Clinics Alkmaar. US/FNAC was performed preoperatively in all these patients. We analysed the results of US/FNAC retrospectively. Pathological axillary node status (sentinel node biopsy and/or axillary lymph node dissection) was used as reference standard. A total of 634 (29.8 %) of 2130 patients had axillary lymph node metastases on final histology. 248 node positive patients (11.6 %) had three or more positive lymph nodes. The accuracy of US/FNAC to detect three or more positive lymph nodes was 89.8 %, sensitivity was 44.8 %, specificity was 95.7 %, PPV was 58.1 %, and NPV was 92.9 %. This study shows a more than adequate accuracy of preoperative US/FNAC to detect three or more positive lymph nodes (89.8 %). However, when US/FNAC was chosen as the only axillary staging method, 6.4 % of all patients (false negative group) would have been undertreated and 3.8 % of all patients (false positive group) would have been overtreated according to the ACOSOG Z0011 criteria.

Grey zone lesions of breast: Potential areas of error in cytology

Fine-needle aspiration cytology (FNAC) of the breast is a rapid, cost-effective, and sensitive procedure to diagnose breast lesions, and was widely employed to diagnose breast lesions in the past. However, in recent times, core needle biopsy of the breast is gaining popularity and acceptability, although FNAC still looms large. There are some intrinsic disadvantages to FNAC, of which the most important is probably difficulty in classification of a significant percentage of breast lesions. Such lesions are usually denoted by the rubric “grey zone lesions of the breast.” This article attempts to review these grey zone lesions and highlight the difficulties in diagnosing them.

Inconclusive or erroneous fine-needle aspirates of breast with adequate and representative material: a cytologic/histologic study

Adequately cellular and representative fine-needle aspirates (FNAs) of breast have a high diagnostic accuracy. There is, however, a recognized category designated as "gray zone" where a definitive diagnosis cannot be reached. We reviewed our experience in this category to identify useful diagnostic parameters. Twenty-four such FNAs with surgical follow-up were retrieved from AUBMC files (2003-2009). Cytology slides were reviewed blindly. All cases were females, 29-73 years. There were three erroneous and 21 inconclusive diagnoses. The majority (15) was invasive adenocarcinomas: two cribriform, four tubular, one lobular, and eight not otherwise specified. The remaining cases were papillary and fibroepithelial tumors (three each), ductal carcinoma in situ, cribriform (two), and one adenomyoepithelioma (AME). Useful diagnostic features included: (1) Biphasic cell population with focal nuclear atypia and intranuclear and cytoplasmic vacuolar inclusions (AME). (2) Complex clusters of epithelial cells with cribriform architecture (cribriform carcinoma). (3) Rigid tubular epithelial structures with abrupt change in diameter, ending in pointed tips with abnormal branching (tubular carcinoma). (4) Cellular stromal fragments (fibroepithelial tumors). (5) Papillary fibrovascular cores, columnar cells, and three-dimensional papillary epithelial fragments (papillary tumors). Myoepithelial cells classically described in benign aspirates were not always a discriminatory factor. The "gray zone" in breast FNA is usually due to overlapping cytologic features of some benign and malignant lesions. Useful distinguishing cytologic features are described.

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.

Indeterminate and erroneous fine-needle aspirates of breast with focus on the 'true gray zone': a review

OBJECTIVE

To review our experience and the literature on inconclusive/erroneous fine-needle aspirates (FNAs) of breast with the focus on the 'true gray zone'. To describe the cytology, differential diagnosis, pitfalls and limitations of common and rare lesions.

STUDY DESIGN

We conducted a literature search focusing on breast FNAs with statistical data of C3 and C4 categories including false-positive and false-negative cases. Similar data from 2003 to 2009 was obtained from our institution.

RESULTS

C3 and C4 categories account for 3-17% of breast FNAs. Contributing factors are technical difficulties, inexperienced pathologists interpreting FNAs of breast and overlap of cytologic features of certain benign and malignant conditions; this last, 'true gray zone' accounts for 2% of cases. Fibroadenoma, proliferative breast lesions, gynecomastia, infiltrating and in situ low-grade adenocarcinomas and tubular, cribriform, lobular and mucinous carcinomas are the most common problematic lesions. Granular cell tumor, adenomyoepithelioma, pregnancy-related lesions, fat necrosis, inflammatory and radiation changes, adenoid cystic carcinoma, spindle-cell lesions and Phyllodes tumor are less common.

CONCLUSION

Inconclusive/erroneous FNAs of breast due to the 'true gray zone' are rare. Most are due to the overlapping cytologic features of some benign and malignant conditions. Practical features that may help arrive at the correct diagnoses are elucidated.

Expression of Ki-67 and p27(Kip1) in fine-needle aspirates from breast carcinoma and benign breast diseases

Cell atypia in breast fine needle aspiration (FNA) can introduce some diagnostic difficulties. Molecules reflecting proliferative cell potential, such as Ki-67 and p27(Kip1) , can help in recognizing the true biological nature of a cell. Thus, the objective of the study was to analyze the difference in Ki-67 and p27(Kip1) cell immunoexpression in breast FNA specimens between fibroadenomas, fibrocystic changes (FCC) with atypia, and breast carcinoma. Microscopic analyses of cell cytomorphology and Ki-67 and p27(Kip1) breast cell immunoexpression were done after standard Pappenheim and immunocytochemical staining (labeled streptavidin-biotin, LSAB) method in autostainer DakoCytomation TechMate™. The study included 50 patients with breast carcinoma, 20 patients with fibroadenoma, and 20 patients with FCC with atypia. High Ki-67 and low or absent p27(Kip1) were found in most patients with breast carcinoma, while majority of FCC with atypia were characterized by low Ki-67 and moderate to high p27(Kip1) cell immunoexpression. Majority of fibroadenomas were associated with low Ki-67 and low to moderate p27(Kip1) cell immunoexpression indicating progressive decrease in cell cycle inhibition, but still not so high proliferative activity as in carcinoma. However, although statistically significant difference for Ki-67 and p27(Kip1) was found between breast lesions in our study, the large ranges observed for each marker make them essentially useless for better cytological diagnosis in a single case. Regarding their opposite role in cell cycle, inverse correlation of Ki-67 and p27(Kip1) was noticed. Poorly differentiated carcinoma cells had mostly high Ki-67 and low p27(Kip1) cell immunoexpression.

[The "gray zone" in organized mammography screening: histocytological correlations]

The National Public Health Program has established the organized mammography screening in Hungary. The aim of this study was to conduct an audit of "gray zone" smears of the organized mammography screening in comparison with histopathological diagnoses.

METHODS

Cytology results were rated to C3 atypia probably benign and C4 suspicious of malignancy.

RESULTS

1361 women had aspiration cytology performed from a total of 47,718 mammography non-negative lesions. 105 (7.8%) were diagnosed as C3, whereas 78 (5.7) as C4. Of the 105 patients with C3 diagnosis 61 (58%) patients underwent surgical biopsy. Histology proved malignancy in 20 (32.8%) cases, and benign lesion in 41 (67.2%) cases. All (100%) of the 78 patients with C4 diagnosis had open biopsies; 69 (88.4%) cases were histologically malignant and 9 (11.6%) cases were benign lesions.

CONCLUSION

The auditing results of fine needle aspiration cytology of "gray zone" in organized mammography screening meet the proposed threshold values. Authors conclude that the "gray zone" category in breast cytology is useful and of value if used judiciously.

Ultrasound-guided vacuum assisted breast biopsy in the assessment of C3 breast lesions by ultrasound-guided fine needle aspiration cytology: results and costs in comparison with surgery

Breast lesions defined C3 at ultrasound (US)-guided fine needle aspiration cytology (FNAC) are probably benign, but exhibit atypias. We evaluate the results of US-guided vacuum assisted breast biopsy (VABB) of these lesions. Patients diagnosed C3 by US-FNAC, submitted to US-VABB and with a minimum follow-up of 36 months or surgery were enrolled. Cost outcome of this diagnostic protocol was evaluated. We evaluated 138 patients with non-palpable C3 lesions. In 2/138 (1.4%) cases VABB results were inadequate. VABB diagnosed: 17/138 (12.3%) malignant and 119/138 (86.2%) benign lesions. In 28/138 cases (20.3%) surgery retrieved 18/28 (64.3%) malignant lesions. One false negative result of VABB was observed. Sensitivity and specificity of VABB resulted 94.4% and 100%. Our diagnostic algorithm estimated a 45% mean decrease of costs using VABB when compared with surgical biopsy of all C3 lesions.

Follow-up of benign screen-detected breast lesions with suspicious preoperative needle biopsies

AIM

To study the outcome of patients with screen-detected breast lesions in whom preoperative core biopsy (CB), or fine needle aspiration cytology (FNAC), or both were suspicious of malignancy or malignant, but the final histology of the excised lesion was benign.

MATERIALS AND METHODS

Thirty-nine patients who fulfilled the above criteria were identified from a prospectively entered database of 192,153 breast screening examinations at the Bedfordshire and Hertfordshire Breast Screening Unit. Thirty-four patients had suspicious or malignant preoperative FNAC and/or CB, and five had FNAC only. Follow-up was mainly by mammograms. Outcome data were collected from hospital case notes and radiology reports.

RESULTS

The median follow-up period was 3 years following excision biopsy. One patient whose excision biopsy histology was atypical ductal hyperplasia developed a mammographically occult carcinoma in the same breast after 24 months. There were no other cancers reported during this time.

CONCLUSION

The problem of suspicious preoperative needle biopsies with benign excision biopsy is uncommon in the breast screening population. These patients are not at an increased risk of being diagnosed with a carcinoma in the subsequent 3 years and may be discharged back to standard breast screening.

Combined use of imaging and cytologic grading schemes for screen-detected breast abnormalities improves overall diagnostic accuracy

BACKGROUND

Numeric grading systems have been validated for the reporting of mammographic abnormalities and for breast cytology. The impact of integrating lesion grades from both disciplines on the accuracy of assessment of screen-detected lesions has not been investigated.

METHODS

In the current study, all lesions were prospectively classified using the Tabar radiologic grading system, as well as the National Health Service Breast Screening Programme (NHSBSP) cytologic reporting system. For lesions assessed between January 1996 and January 2003, based on final histology or 12 months of follow-up, positive predictive values (PPV) were calculated for each imaging grade and for each cytologic grouping. After integration of the data, changes in the PPV and the negative predictive values (NPV) of cytology among lesions with varying imaging grades were tracked.

RESULTS

Data were retrieved for 4806 lesions. The differences in the rates of malignancy for lesions in the different imaging grades were significant (Grade 5, 95.8%; Grade 4, 54.6%; Grade 3, 11.6%) (P < 0.001). Similarly, the cytologic categories stratified lesions into groups with significantly different rates of malignancy (positive, 99.5%; suspicious, 89.2%; atypical, 43.4%; benign, 5.7%; inadequate, 33.3%) (P < 0.001). Integration of cytologic results with the imaging grade of lesions led to significant improvements in the PPV and NPV. Positive smears were likely to represent malignant lesions in 99.9% of Grade 5 lesions, 99.2% of Grade 4 lesions, and 95.2% of Grade 3 lesions (P < 0.0001). Similarly, negative cytology corresponded to a nonmalignant lesion in 99% of Grade 3 lesions, 81.6% of Grade 4 lesions, and in only 45.5% of Grade 5 lesions (P < 0.001).

CONCLUSIONS

The integration of numeric grading schemes for breast imaging and cytology improves the accuracy of assessment of screen-detected lesions. Because 99.9% of Grade 5 lesions with positive cytology are malignant, core biopsy confirmation may not be required in this group.

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.

Interpretation of fine needle aspiration cytology of the breast: a comparison of cytological, frozen section, and final histological diagnoses

This study examines the performance of the preliminary, on-site interpretation by the pathologist of fine needle aspiration (FNA) cytology smears compared to the final cytology report, the frozen section diagnosis and the final histopathological report. We found that both the preliminary and the final cytology reports gave satisfactory results over the minimum standards for quality assurance required by both the Norwegian breast screening programme and the NHS BSP in the UK with the exception of the 'suspicious' rate. We noted that the preliminary report had fewer false negatives (2.1%) than the final report (4.3%). We show that an unequivocal cytological diagnosis of malignancy is a reliable diagnosis, and in cases where mammography/ultrasonography and clinical examination are in agreement with FNA, frozen section examination is unnecessary. However, cases with a suspicious or equivocal FNA should be considered for frozen section analysis.

Predictive power of cytomorphological features in equivocal (C3, C4) breast FNAC

Definitive immediate diagnosis in breast fine needle aspiration cytology (FNAC) remains the aim for cytopathologists. We reviewed 72 consecutive equivocal (C3 and C4) aspirates with respect to 16 cytomorphological criteria. We assessed the power of each criterion at predicting either a malignant [positive predictive value (PPV)] or a benign [negative predictive value (NPV)] diagnosis by correlation with follow-up histology. Blind review led to 34% of cases being correctly definitively diagnosed. Eccentrically placed epithelial cell nuclei (PPV = 88%, sensitivity = 67%, specificity = 87%) and coarse nuclear chromatin (PPV = 81%, sensitivity = 72%, specificity = 83%) are the features that are most useful in predicting malignancy in this selected series. The presence of myoepithelial cells within epithelial groups is not a good indicator of a benign diagnosis (NPV = 24%, sensitivity = 80%, specificity = 53%).

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

The diagnosis of atypia in breast fine-needle aspiration (FNA) continues to be an area of debate in cytology practice. The aim of this study was to assess the clinical significance of this term and to evaluate potential morphological criteria, which would determine the patient's outcome. A computer-based search was carried out to retrieve breast FNAs performed between 1990 and 2000 that were diagnosed as atypical. Cases followed by surgical resection were reexamined for the presence of morphological features potentially differentiating benign and malignant lesions. Out of 1,568 breast FNAs, there were 64 cases (4%) with a diagnosis of atypia. Thirty-eight cases had surgical follow-up material that revealed malignancy in 14 cases (37%) and benign lesions in 24 cases (63%). The benign diagnostic categories included fibrocystic change (12/24), fibroadenoma (3/24), tubular adenoma (2/24), and nonspecific findings (7/24). The malignant diagnoses included ductal carcinoma (9/14), lobular carcinoma (3/14), ductal carcinoma in situ (DCIS; 1/14), and tubular carcinoma (1/14). The evaluation of cytological criteria used to differentiate benign from malignant lesions (i.e., cellularity, loss of cohesion, myoepithelial cells, nuclear enlargement, nuclear overlap, prominent nucleoli) revealed significant overlap between benign and malignant cases, particularly in cases of fibroadenoma, tubular adenoma, and proliferative breast disease. The surgical follow-up of four hypocellular cases revealed lobular carcinoma in two cases and ductal carcinoma in the remaining two cases. Our study confirmed that the diagnosis of atypia is clinically significant because it is associated with a high probability of malignancy. No morphological criterion is able to reliably differentiate benign and malignant lesions in cases diagnosed with atypia. Diagnosis of atypia is particularly significant in hypocellular cases. We recommended that breast FNAs with a diagnosis of atypia be evaluated further histologically.

Excision biopsy findings of patients with breast needle core biopsies reported as suspicious of malignancy (B4) or lesion of uncertain malignant potential (B3)

AIMS

The UK National Health Service Breast Screening Programme has proposed five categories for reporting breast needle core biopsies. The majority of cores are reported as benign (B1), normal (B2) or malignant (B5). The predictive value of the two borderline categories suspicious of malignancy (B4) and lesion of uncertain malignant potential (B3) was studied.

METHODS AND RESULTS

Over a 2-year period a total of 3822 breast needle core biopsies were performed, with 2997 from symptomatic patients and 825 from women undergoing mammographic screening, including 43 B4 reports (40 patients) and 120 B3 reports (116 lesions in 115 patients). The frequencies of B4 (2.5% versus 0.7%) and B3 cores (7.3% versus 2.0%) were both higher in screening than in symptomatic patients. B4 was most commonly used for small fragments of atypical cells separate from the main core or focal atypical intraductal proliferations. The criteria for calling a core B3 were: atypical intraductal epithelial proliferations (including foci that in excision specimens would be classified as atypical ductal hyperplasia), lobular neoplasia, radial scar, papillary lesion, fibroepithelial lesion with cellular stroma and spindle cell proliferations. Excision biopsies were performed in 39 patients with B4 core and 96 with B3 core. Invasive carcinoma or ductal carcinoma in situ was seen in 33 of the patients with B4 (85%) and in 29 of those with B3 cores (25%). Some categories of B3 core were associated with a higher rate of malignancy (40% for atypical intraductal epithelial proliferations and 46% for lobular neoplasia).

CONCLUSIONS

The positive predictive value for carcinoma is high following a B4 core (86%). The lesion should be excised, but definitive cancer treatment is not appropriate. In some cases a definite diagnosis of malignancy can be made on repeat core. The B3 group is more heterogeneous and has a lower rate of malignancy on further biopsy (25%). The majority of B3 lesions require excision. All these patients should be discussed at multidisciplinary meetings.

An audit of the accuracy of fine needle aspiration using a liquid-based cytology system in the setting of a rapid access breast clinic

We have assessed the effectiveness and accuracy of reporting fine needle aspirates of the breast (FNAB) using a liquid-based cytology (LBC) system (the Cytospin) method) in the pressure situation of a rapid access clinic (RAC). We have reviewed every case from the RAC from June 1997 to February 2001 inclusive. There were 1322 cases, which accounted for 26% of the total FNAB received in our department over the period. There were 323 cancers and 999 benign cases in the group. The inadequate/nondiagnostic rate (C1) was 18%. The absolute sensitivity, including C1 cases, was 73% with the complete sensitivity being 90%. The groups of 'atypical, probably benign' (C3) and 'suspicious, probably malignant' (C4) accounted for a total of 6.2%. There were 28 false negative cases and 1 false positive case (a borderline phyllodes tumour). Comparing our results with the standards recommended by the NHSBSP has shown that the diagnosis of FNAB using this LBC method is feasible, accurate and reliable even in the pressure situation of a RAC.