While Fine needle aspiration cytology (FNAC) and mammography are both used to diagnose breast lesions, FNAC is generally more accurate than mammograms for predicting breast cancer. It is also gaining popularity as an early detection tool due to its rapid and straightforward procedure, cost-effectiveness, and minimal risk of complications. Deep learning enhances breast cancer detection by extracting crucial features, yielding highly accurate results compared to conventional techniques. Classical machine learning is less time-intensive and requires fewer parameter adjustments. This work is presented as a proof-of-concept study on FNAC images obtained from two centers. It explores eighteen hybrid architectures that are developed and evaluated, combining the strength of deep learning techniques- Inception-V3, MobileNet-V2, and DenseNet-121 for feature extraction, with three machine learning classifiers (Support Vector Machine, Decision Tree, and k-Nearest Neighbours) for binary classification of fine needle aspiration cytology images of the breast. Our study is based on an indigenously collected dataset of 427 images (152 benign and 275 malignant), which was later expanded through augmentation to 2,866 images (1216 benign and 1,650 malignant). The hybrid model, which combines feature extraction from MobileNet-V2 and DenseNet-121 in a concatenated architecture, achieves the highest internal test accuracy of 98.26% when paired with an SVM classifier. It also achieves the best-known sensitivity (97.95%) and specificity (98.48%). The explainability model, which utilizes Grad-CAM, achieved 95% positive clinical validation by expert pathologists, underscoring the model's trustworthiness and interpretability-critical for clinical adoption and decision-making support. The proposed hybrid model, with its impressive metrics and validation rate, underscores the model's ability to provide clear, interpretable insights that support clinical decision-making.

Fine-needle aspiration cytology (FNAC) remains widely used for the evaluation of palpable breast lesions, particularly in resource-limited settings, though histopathology is the gold standard. The International Academy of Cytology (IAC) Yokohama System provides a standardized five-tier reporting framework with defined risk of malignancy (ROM). This study aimed to evaluate its diagnostic performance, reproducibility, and applicability in a tertiary care setting. A total of 548 breast FNACs from 533 patients were reclassified both prospectively and retrospectively according to the IAC Yokohama categories. Histological correlation was available in 228 cases. Interobserver agreement was assessed among two senior cytopathologists and one junior pathologist using unweighted and weighted kappa statistics. Diagnostic performance was calculated against histology using three definitions of test positivity (Cat-5 only; Cat-4 & 5; Cat-3-5). A total of 548 FNACs from 533 patients were reclassified using the IAC Yokohama system: Cat-1 (36, 6.6%), Cat-2 (318, 58.0%), Cat-3 (14, 2.6%), Cat-4 (25, 4.6%), and Cat-5 (155, 28.3%). Histological correlation was available in 228 cases. The observed ROM was 50% for Cat-1, 7.9% for Cat-2, 45.5% for Cat-3, 93.8% for Cat-4, and 100% for Cat-5. Diagnostic accuracy improved with reclassification: in Group A (Cat-5 positive), sensitivity increased to 78.4% and specificity was 100%; in Group B (Cat-4 & 5 positive), sensitivity was 90.9% and specificity was 97.9%; and in Group C (Cat-3-5 positive), sensitivity reached 94.7% with a specificity of 89.6%. ROC analysis confirmed superior discrimination for the Yokohama system (AUC 0.94 vs. 0.88 for the original). Interobserver reproducibility was excellent, with weighted kappa values of 0.954 (P1 vs. P2), 0.942 (consensus vs. P3), and 0.939 (P2 vs. P3). Agreement was highest in benign and malignant categories and lowest in atypical and suspicious groups. The IAC Yokohama System showed high diagnostic accuracy, excellent reproducibility, and reliable risk stratification. By reducing false negatives and minimizing equivocal reporting, it improved alignment with histology compared with the conventional descriptive system, supporting its routine use in breast cytology practice.

Abstract Background: Diagnosis of breast cancer is usually done by triple assessment, which includes clinical, radiological, and pathological examination. Fine-needle Aspiration Cytology (FNAC) provides significant benefits as a diagnostic test with its rapidity of diagnosis, low cost, high rate of acceptance by patients, and high accuracy. In the present study, we retrieved the breast FNAC reports from the cytopathology laboratory and applied the International Academy of Cytology (IAC) Yokohama reporting system. Materials and Methods: The study encompassed all breast FNAC samples received in the laboratory from January 2024 to December 2024. Conventional smears were prepared from palpable lumps in the breast. These slides were fixed in ethanol. Following fixation, they were stained with hematoxylin and eosin. All the cases were classified according to the IAC Yokohama reporting system and correlated with histopathology wherever possible. Results: The study included a total of 257 breast aspirates from January 2024 to December 2024. The age group of patients ranged from 17 years to 72 years, with the majority of cases belonging to the 3 rd and 4 th decades, and 12 were male. Of the total 257 cases, 11 cases (4.2%) belonged to Category I (insufficient), 168 (65.6%) to Category II (benign), 21 (8.2%) to Category III (atypical), 13 (5%) to Category IV (suspicious for malignancy), and 44 (17%) to Category V (malignancy). Conclusion: IAC Yokohama’s use of FNAC for breast diagnostics offers an efficient and minimally invasive approach for the early detection of breast abnormalities, providing healthcare professionals with valuable insights to guide treatment decisions.

Objective:Breast fine-needle aspiration cytology (FNAC) is a rapid, cost-effective, and minimally invasive diagnostic procedure. The diagnosis of a proliferative breast disease with atypia (PBDA) is established based on the presence of areas with disordered cellular arrangement and mildly discerned cytological features. We have aimed to explore the cytohistological correlation of PBDA on FNAC.Material and Methods:A review of the hospital database was undertaken to retrieve cases of breast FNAC diagnosed as PBDA between January 2011 and September 2020.Results:A total of 3125 breast FNAC specimens were examined, and 107 (3.4%) of them received the diagnosis of PBDA. A total of 68 PBDA cases were included in this cytohistological evaluation. The risk of malignancy was 44%. Except for one case, all of the invasive or microinvasive carcinomas were grade 1 or 2 malignancies according to the Nottingham grading system of breast cancers. The result of a repeat FNAC of the case with a poorly differentiated invasive breast cancer was reported as a high-grade malignancy. A statistically significant correlation was observed between older age and malignant outcome (P < 0.001).Conclusion:This is one of the largest datasets of cases with PBDA. Based on the advanced age of the patient, and relevant clinical and radiological information, cytopathological diagnosis of PBDA may prompt the clinician to take further action.

BackgroundBreast lesions can occur in individuals of all age groups and may include a range of conditions, from benign abnormalities to malignant tumors. Among these, breast cancer is one of the most frequently diagnosed cancers worldwide. Methods used to diagnose breast lesions include histopathology studies and flow cytometry DNA analysis. Some lesions, like cellular fibroadenoma and benign phyllodes tumors, are difficult to differentiate from each other. As their treatment modalities differ from each other, it is important to manage the condition with care.This study emphasizes the importance of timely diagnosis and treatment of various breast conditions to ensure the best possible outcome for patients.ObjectiveTo retrospectively analyze the histopathological patterns of breast lesions, along with their demographic and clinical characteristics, among patients presenting to a specialty hospital over a 5-year period.MethodsA retrospective study was conducted by including the breast biopsy, mastectomy, and Fine Needle Aspiration Cytology (FNAC) reports of all patients who presented with various breast lesions at Terna Speciality Hospital and research center during the period of January 2017 to December 2022. Various demographic and clinical information was gathered through the histopathology request forms and registry. The authors also looked at histopathology slides of various instances that occurred during the research period.ResultsThe mean age of diagnosis of various breast lesions was found to be 34.18 (SD +/- 14.92). 83% of lesions presented at less than 50 years of age and 17% at more than 50 years. 97% of the total lesions studied were found among the female population. 98% of all lesions presented with a palpable mass, out of which most (64%) lesions were between 1 and 5 cm in size. The majority of the lesions (45.9%) were right-sided, and only 7.2% were bilateral. Most of the lesions studied presented in the upper outer quadrant.Most of the benign and inflammatory lesions studied presented in individuals aged 21-30 years, and malignant lesions were found predominantly among individuals aged 61-70 years. No inflammatory lesions were found beyond the age of 60 years, and only one malignant lesion was found below 20 years. Among all lesions studied, benign lesions were most common, found in 406 subjects. 18.5% of all lesions were malignant in nature, among which the majority were invasive breast cancer.ConclusionBreast cancer is a complex and heterogeneous disease with varying patterns. Most of the lesions studied were benign in nature, of which the most common was fibroadenoma. The most common malignant lesion in the study was invasive breast cancer - nonspecific type.Understanding the histopathological patterns of breast lesions is essential for improving the diagnostic and treatment outcomes of this disease.

Breast cancer is the most prevalent cancer among women worldwide. In developing countries, fine needle aspiration cytology (FNAC) is commonly used for screening to reduce mortality rates. The International Academy of Cytology has established the Yokohama system to enhance diagnostic clarity and communication between pathologists and clinicians. A triple test approach, incorporating clinical evaluation, imaging, and FNAC, can further improve patient care for breast lesions and may enhance the Yokohama System's effectiveness. A prospective study about breast FNAC was done over a period of one year, from October 2022 to September 2023. The study involved patients with breast lesion referred for FNAC in the department of Pathology. The FNAC results were further classified using the Yokohama system for reporting breast cytopathology, 2016. The cytological findings were correlated with available histopathological results. In the study of 104 cases, 60 (57.7%) of whom had available histopathology results, breast lesions were categorized using the Yokohama system as: 7.7% insufficient, 47.1% benign, 26.9% atypical, 2.9% suspicious of malignancy, and 15.4% malignant. The risk of malignancy varied by category: 0% for category 1, 3.2% for category 2, 47% for category 3, and 100% for categories 4 and 5. The maximum sensitivity was 94.7% when considering atypical, suspicious, and malignant cases as positive. The highest specificity was 97.56% for malignant cases alone, while the best diagnostic accuracy was 83.3% when both malignant and suspicious cases were counted as positive. The Yokohama system effectively classified borderline lesions, facilitating early detection and improved management options. By integrating FNAC with standardized reporting, healthcare providers can make informed decisions, enhancing the diagnosis and treatment of breast lesions.

Standardized reporting of breast FNAC using the International Academy of Cytology Yokohama system and its comparison with histopathology: a cross-sectional study

The International Academy of Cytology (IAC) Yokohama System has developed a standardized system of reporting breast cytology. The current study aimed to apply the newly proposed YOKOHAMA classification system along with American College of Radiology Breast Imaging Reporting and Data system (ACR-BI-RADS) scoring to breast fine-needle aspiration cytology (FNAC) cases from the department archives and to assess the risk of malignancy (ROM) for each category. All breast FNACs done between January 20017 and June 2023 were reclassified according to the proposed IAC Yokohama reporting system. Histopathological correlation of the IAC Yokohama system and BI-RADS was done wherever available. A three-category approach was followed based on benign versus malignant, and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated using histopathology as the gold standard. A total of 2130 breast FNACs were performed, of which 469 had a histopathological correlation and 892 had a BI-RADS correlation. The ROM for insufficient, benign, atypical, suspicious, and malignant categories were 29.16%, 3.28%, 28.57%, 100%, and 92.18%, respectively. Maximum specificity (96.8%) was observed when only malignant (cat A) and when both suspicious and malignant cases (Cat B) were taken as positive test results. Highest sensitivity (92.7%) was achieved when atypical, suspicious, and malignant cases were taken as positive test results (Cat C) and highest diagnostic accuracy (94.8%) was seen in category B. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy of BI-ADS were 78.67%, 92%, 85.5%, 87.8%, and 87%, respectively. FNAC and imaging are the key modalities for diagnosing breast lesions. The IAC Yokohama system along with ACR-BI-RADS provides a simple yet useful approach for effectively categorizing the different breast lesions, which is useful for patient management and risk stratification.

Erratum: Breast fine-needle aspiration cytology in the era of core-needle biopsy: what is its role?

499 Aspiration For Knowledge: A Workflow for Enhancing Education in Breast Fine Needle Aspiration Cytology

An insufficient/inadequate diagnosis on fine-needle aspiration cytology (FNAC) of the breast is not an uncommon diagnostic dilemma. This study aims to review the rate and clinical features predicting an informative...

Fine-needle aspiration cytology (FNAC) has long been recognized as a minimally invasive, cost-effective, and reliable diagnostic tool for breast lesions. However, with the advent of core-needle biopsy (CNB), the role of FNAC has diminished in some clinical settings. This review aims to re-evaluate the diagnostic value of FNAC in the current era, focusing on its complementary use alongside CNB, the adoption of new approaches such as the International Academy of Cytology Yokohama System, and the implementation of rapid on-site evaluation to reduce inadequate sample rates. Advances in liquid-based cytology, receptor expression testing, molecular diagnostics, and artificial intelligence are discussed, highlighting their potential to enhance the diagnostic accuracy of FNAC. Despite challenges, FNAC remains a valuable diagnostic method, particularly in low-resource settings and specific clinical scenarios, and its role continues to evolve with technology.

ABSTRACT Background: In 2016, the International Academy of Cytology (IAC) established a reporting system for breast fine-needle aspiration (FNA) cytology. This system proposed five categories in its classification: category for insufficient; category 2 for benign; category 3 for atypical, probably benign; category 4 indicating suspicious for malignancy; and category 6 for malignant. Aims and Objectives: The aim of the present study was to review and categorize the breast FNA samples according to the new system of reporting, to assess the risk of malignancy (ROM) for each category, and to assess the diagnostic yield of breast FNA biopsy (FNAB). Materials and Methods: The present retrospective study was conducted in the department of pathology, IGMC, Shimla from January 2019 to December 2019. All the samples during this period were included in the study. Results: A total of 405 breast cytology cases were included in the present study. The FNA findings were correlated with histopathology in 82 cases. The ROM for each category was 16.6% for insufficient, 3.7% for benign, 0% for atypical for malignancy, 100% for suspicious for malignancy, and 92.3% for malignant category. Conclusion: The IAC Yokohama system for reporting breast FNA cytology helps in standardizing reports and easier communication of the pathologists with treating surgeons. It offers a ROM for each category which helps during follow-up of patients. Utilizing the system in day-to-day reporting will improve diagnostic clarity and management.

Introduction: Breast malignancy is one of the common causes of morbidity and mortality among females. Screening of breast lumps by Fine Needle Aspiration Cytology (FNAC) is included in triple approach and is easy to perform. Accuracy of diagnosis can be further enhanced by histopathological confirmation. Aims: The role of FNAC in diagnosis of breast lumps and to determine its diagnostic accuracy. Methods: This was a hospital based prospective study conducted over the period of one year (from March 2023 to February 2024) in department of Pathology, Nepalgunj Medical College, Kohalpur, Nepal. Patients who presented with breast lump underwent FNAC with biopsy for histopathological study was included in the study. Cytological opinion was categorized according to International Academy of Cytology Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology criteria reporting system. Histological correlation was carried out in patients who went surgical excision or biopsy of the lesion. Results: Most common diagnosis on cytology was fibroadenoma. According to International Academy of Cytology Yokohama reporting system C2 (benign) was most common reported category (19 cases). On histopathological study, 19 cases were benign and 13 cases were malignant with most common benign lesion being fibroadenoma and all malignant cases were Invasive ductal carcinoma. All cases diagnosed as malignant on cytology were concordant on histopathology. Three benign, one atypical and one suspicious on cytology were malignant on histopathological study. The sensitivity and specificity of FNAC was 84.2% and 69.2% respectively. Diagnostic accuracy of FNAC was 59.4%. Conclusion: Breast FNAC is a rapid and reliable tool for evaluation and have high sensitivity and specificity.

The International Academy of Cytology (IAC) has developed a standardized approach for reporting the findings of breast fine-needle aspiration cytology (FNAC). Accordingly, there are five chief categories of breast lesions, C1 (insufficient material), C2 (benign), C3 (atypical), C4 (suspicious), and C5 (malignant). The prognostication and management of breast carcinoma can be performed readily on the basis of this classification system. The aim of this study was to classify various breast lesions into one of the above-named categories and to further grade the C5 lesions specifically using the Robinson system. The latter grades were then correlated with modified Scarff-Bloom-Richardson (SBR) grades. This retrospective study was undertaken in the pathology department of a hospital located in the urban part of the city of Bangalore. All FNAC procedures performed on breast lumps spanning the year 2020 were included in the study. A total of 205 breast lesions was classified according to the IAC guidelines into C1 (6 cases, 2.9%), C2 (151 cases, 73.7%), C3 (13 cases, 6.3%), C4 (5 cases, 2.5%), and C5 (30 cases, 14.6%) groups. The C5 cases were further graded using Robinson's system. The latter showed a significant correlation with the SBR system (concordance=83.3%, Spearman correlation=0.746, Kendall's tau-b=0.736, kappa=0.661, standard error=0.095, p≤.001). A standardized approach for FNAC reporting of breast lesions, as advocated for by the IAC, improves the quality and clarity of the reports and assures diagnostic reproducibility on a global scale. Further, the cytological grading of C5 lesions provides reliable cyto-prognostic scores that can help assess a tumor's aggressiveness and predict its histological grade.

Introduction: Fine-needle aspiration cytology (FNAC) specimens are widely utilized for the diagnosis and molecular testing of various cancers. We performed a comparative proteomic analysis of three different sample types, including breast FNAC, core needle biopsy (CNB), and surgical resection tissues. Our goal was to evaluate the suitability of FNAC for in-depth proteomic analysis and for identifying potential therapeutic biomarkers in breast cancer. Methods: High-throughput proteomic analysis was conducted on matched FNAC, CNB, and surgical resection tissue samples obtained from breast cancer patients. The protein identification, including currently established or promising therapeutic targets, was compared among the three different sample types. Gene Ontology (GO) enrichment analysis was also performed on all matched samples. Results: Compared to tissue samples, FNAC testing revealed a comparable number of proteins (7,179 in FNAC; 7,196 in CNB; and 7,190 in resection samples). Around 85% of proteins were mutually identified in all sample types. FNAC, along with CNB, showed a positive correlation between the number of enrolled tumor cells and identified proteins. In the GO analysis, the FNAC samples demonstrated a higher number of genes for each pathway and GO terms than tissue samples. CCND1, CDK6, HER2, and IGF1R were found in higher quantities in the FNAC compared to tissue samples, while TUBB2A was only detected in the former. Conclusion: FNAC is suitable for high-throughput proteomic analysis, in addition to an emerging source that could be used to identify and quantify novel cancer biomarkers.

BackgroundFine-needle aspiration cytology (FNAC) of the breast is a well-established technique that aids in the preoperative identification and differentiation between nonneoplastic and neoplastic breast lesions. Breast lesions can be efficiently categorized into different cytological groups using the International Academy of Cytology (IAC) Yokohama System. The aim of this study was to classify breast lesions based on the proposed Yokohama system of reporting breast cytology and identify the need for a unified system of reporting breast lesions.Materials and methodsThis retrospective descriptive study was performed in the Department of Pathology, Government Medical College, Datia, M.P. from January 2019 to June 2023. A total of 762 FNAC slides reported during this period were retrieved, re-examined and reclassified according to the IAC Yokohama System. Histopathological diagnoses were also retrieved and correlated with the cytological findings wherever available.ResultsIn the present study, a total of 762 smears of breast fine needle aspirations were included and categorized using the IAC Yokohama System. There were 3.8% cases (29/762) in the C1 category (insufficient), 71.6% cases (545/762) in the C2 category (benign), 6.3% cases (48/762) in the C3 category (atypical), 3.1% cases (24/762) in the C4 category (suspicious for malignancy) and 15.2% (116/762) cases in the C5 category (malignant).ConclusionFNAC is a reliable diagnostic technique for the evaluation and management of breast lesions prior to surgery. Implementing the IAC Yokohama System for reporting breast cytopathology enhances the accuracy of diagnosing breast lesions, reduces missed diagnoses, and offers reliable estimates of risk of malignancy. Adopting the Yokohama system is a crucial first step in boosting the overall effectiveness of breast cytology reporting among clinicians and pathologists, which will ultimately lead to improved communication and patient care.

Abstract Background: Breast lumps pose a significant health concern globally, contributing to both illness and death. The International Academy of Cytology (IAC) Yokohama system has established a uniform method for reporting breast cytology, categorizing it into five groups: inadequate, benign, atypical, suspicious, and malignant. Aims and Objectives: This study primarily aimed to evaluate breast lesions using the IAC Yokohama System and compare the results with those of corresponding histopathological biopsies. Additionally, the study aimed to analyze the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of breast fine-needle aspiration cytology (FNAC) and determine the risk of malignancy associated with each category. Materials and Methods: In this study, 92 cases were analyzed and categorized according to the IAC Yokohama System. Sensitivity, specificity, PPV, NPV, diagnostic accuracy, and risk of malignancy were determined based on histopathological diagnosis, which was considered the reference standard. Results: Among the 92 breast FNACs, the risk of malignancy for the categories insufficient, benign, atypical, suspicious, and malignant were 0%, 0%, 18.75%, 100%, and 100%, respectively. The highest sensitivity (100%) was achieved when considering atypical, suspicious, and malignant cases as positive results. The specificity was highest (100%) when only malignant or both malignant and suspicious cases were considered positive results. The highest diagnostic accuracy (95.65%) was observed when including malignant and suspicious cases as positive results. Conclusion: Implementing the IAC Yokohama System for reporting breast cytopathology through structured reporting will enhance the quality, clarity, and reproducibility of reports among pathologists and clinicians, which would result in enhanced patient care and management.

Utilizing the Yokohama System of the International Academy of Cytology to Report Breast Fine Needle Aspiration Cytology

Objective: The International Academy of Cytology (IAC) Yokohama system was used to categorize breast lesions as the major goal of this investigation. Methods: Between January 2022 and March 2023, this study on breast fine needle aspiration cytology (FNAC) was carried out at a tertiary care facility in north India. This System of reporting breast cytopathology was used to classify a total of 100 patients. Histopathology correlation was available in 40 cases; Malignancy risk, sensitivity, specificity, and diagnostic precision were assessed. Results: Breast FNAC cytology was divided into five groups using the new IAC Yokohama system and discovered C1: Insufficient material (6%), C2: Benign type (72%), C3: Atypical type (05%), C4: Suspicious type of malignancy (06%), C5: Malignancy (11%). When histopathological reports were available, FNACs were connected with them. The likelihood of cancer, the precision, sensitivity, and specificity of the diagnosis were all calculated. Conclusion: The IAC Yokohama System for reporting breast cytopathology governs how breast FNAC are categorized, which offers an excellent method for reporting breast cytopathology with a uniform method of reporting and clear definition of each category as well as clear communication between pathologists and clinicians regarding the risk of malignancy and subsequent management.