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

Introduction: Fine Needle Aspiration Cytology (FNAC) is a rapid, minimally invasive and cost-effective procedure with a high sensitivity rate of 92-95% and high Positive Predictive Value (PPV) approaching 100% for the diagnosis of breast malignancies. International Academy of Cytology (IAC) Yokohama system for reporting breast FNACs had been established in 2016 to bring consistency and uniformity of breast cytology reporting. Aim: To classify the breast lesions according to the IAC Yokohama system for cytological reporting of breast lesions. Materials and Methods: This was a retrospective six years study carried out in the Department of Pathology, Karpaga Vinayaga Institute of Medical Sciences, Chinnakolambakkam, Tamil Nadu, India. All females breast FNAC cases reported during the year January 2015 to December 2020 were included in the study according to the inclusion criteria. Relevant clinical and pathological data including the FNAC reports were retrieved from the medical records of the department. Corresponding FNAC smears stained with Haematoxylin and Eosin (H&E) and Papanicolaou stains were reviewed and double-checked with the FNAC reports. All those cases were grouped according to the IAC Yokohama System. Statistical analysis was carried out using Statistical Package for the Social Sciences (SPSS) version 23.0. Results: Of the total 381 female breast FNACs, majority (60%) of them belonged to the age group of 21-40 years. The predominant presenting symptom was palpable breast lump (73%) and Upper Outer Quadrant (UOQ) was involved in 65% of cases. Out of 381 cases, 297 (78%) were benign, 52 (13.6%) were malignant and 32 (8.4%) were inadequate for diagnosis. Total 73.8% cases belonged to “C2” category and fibroadenoma was the most prevalent lesion. Pearson Chi-square test showed highly significant association between patient’s age above 40 years and the risk of having a malignant breast lesion (p<0.0001). Conclusion: FNAC is an effective diagnostic modality for preoperative diagnosis of breast lesions thereby facilitating proper treatment at an early stage of the disease. Also adherence to the standardised cytological reporting system like IAC Yokohama system will ensure quality assurance across various institutions, thereby strengthening the healthcare services.

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.

Introduction: Breast cancer affects 2.1 million women each year and is the most common cancer among females, followed by lung, colorectum, uterus, and cervix. Breast cancer accounted for 6,26,679 (6.6%) deaths in 2018. Breast cancer incidence is on the rise in every part of the globe, including developed countries. Fine Needle Aspiration Cytology (FNAC) shows high sensitivity, specificity, and accuracy in evaluation of breast lesions. FNAC is part of the triple test and is the gold standard for assessment. The new reporting system for breast FNAC, proposed by the International Academy of Cytology (IAC) Yokohama Breast Cytopathology System, has standardised the reporting system to categorise breast lesions and as unmasked the diagnostic dilemma faced by reporting cytopathologist. Aim: The study aimed to categorise the samples according to IAC Yokohama Breast Cytopathology System and assess the Risk of Malignancy (ROM) for each category and increase the diagnostic yield of breast FNAC. Materials and Methods: A retrospective cohort study included 1,467 breast FNAC cases, which were retrieved and reclassified based on the newly proposed IAC Yokohama System into five categories during January 2017-December 2018 in Kidwai Memorial Institute of Oncology (KMIO), Bangalore. Histopathology correlation was done, and the Risk of Malignancy (ROM) was assessed whenever possible. The study results were analysed using Microsoft excel 2007, sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), and accuracy ratios were calculated using the MedCalc diagnostic test evaluation calculator, keeping histologic diagnosis as the gold standard. Results: Re-categorisation of 1,467 cases was done according to the Yokohama breast cytopathology system as insufficient material, benign, atypical, suspicious for malignancy, and malignant. The histopathology diagnosis was available in 1,069 cases. The respective ROM for each category was, 7.6% for category 1 (Insufficient), 15.26% for category 2 (Benign), 65.38% for category 3 (Atypical), 83.33% for category 4 (Suspicious) and 99.18% for category 5 (Malignant). Considering malignant cases as positive, sensitivity-86.75%, specificity-97.32%, PPV-99.19%, NPV-66.06% and accuracy of 88.96% was deduced. Conclusion: It is recommended to incorporate the IAC Yokohama system to categorise breast cytopathology with uniform terminologies. This will help diagnose breast lesions more consistently and accurately, which in turn helps the clinician manage the disease and predict the ROM and the patient outcome.

Background: Worldwide breast malignancy is the major cause for mortality among women. Screening and early detection are crucial. Grey zones of uncertainty in cytomorphological differentiation of benign from malignant lesions can be overcome by Yokohama system of classification. Aims and Objectives: The objectives of this study are as follows: (1) To categorize Breast fine needle aspiration cytology (FNAC) samples according to the international academy of cytology (IAC) Yokohama system. (2) To assess the diagnostic accuracy, sensitivity, specificity, and risk of malignancy (ROM) for each category. Materials and Methods: A retrospective study of 144 breast FNAC cases with histopathological diagnosis was done based on Yokohama System from January 2018 to December 2020. ROM in each category was calculated. The study results were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) considering histological diagnosis as the gold standard. Results: Recategorization of 144 cases with histopathological diagnosis was done according to Yokohama system as insufficient material, benign, atypical, suspicious for malignancy, and malignant. The respective ROM for each category was, 7.6% for Category-1 (Insufficient), 15.26% for Category-2 (Benign), 65.38% for Category-3 (Atypical), 83.33% for Category-4 (Suspicious), and 99.18% for Category-5 (Malignant). Considering malignant cases as positive, sensitivity – 86.75%, specificity – 97.32%, PPV – 99.19%, NPV – 66.06%, and accuracy of 88.96% were deduced. Conclusion: Incorporation of IAC Yokohama system to categorize breast cytopathology using uniform terminologies provides diagnostic clarity, consistency, and accuracy in reporting, which in turn helps the clinician to predict the ROM and patient outcome.

Background: Worldwide breast malignancy is the major cause for mortality among women. Screening and early detection are crucial. Grey zones of uncertainty in cytomorphological differentiation of benign from malignant lesions can be overcome by Yokohama system of classification. Aims and Objectives: The objectives of this study are as follows: (1) To categorize Breast fine needle aspiration cytology (FNAC) samples according to the international academy of cytology (IAC) Yokohama system. (2) To assess the diagnostic accuracy, sensitivity, specificity, and risk of malignancy (ROM) for each category. Materials and Methods: A retrospective study of 144 breast FNAC cases with histopathological diagnosis was done based on Yokohama System from January 2018 to December 2020. ROM in each category was calculated. The study results were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) considering histological diagnosis as the gold standard. Results: Recategorization of 144 cases with histopathological diagnosis was done according to Yokohama system as insufficient material, benign, atypical, suspicious for malignancy, and malignant. The respective ROM for each category was, 7.6% for Category-1 (Insufficient), 15.26% for Category-2 (Benign), 65.38% for Category-3 (Atypical), 83.33% for Category-4 (Suspicious), and 99.18% for Category-5 (Malignant). Considering malignant cases as positive, sensitivity – 86.75%, specificity – 97.32%, PPV – 99.19%, NPV – 66.06%, and accuracy of 88.96% were deduced. Conclusion: Incorporation of IAC Yokohama system to categorize breast cytopathology using uniform terminologies provides diagnostic clarity, consistency, and accuracy in reporting, which in turn helps the clinician to predict the ROM and patient outcome.

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.

Stratification of breast lesions for appropriate management is achieved through an integration of clinical examination, imaging, and fine needle aspiration biopsy (FNAB). The current study aimed to evaluate the combined effectiveness of the widely used Breast Imaging-Reporting and Data System (BI-RADS) with the recently proposed International Academy of Cytology (IAC) Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology. A retrospective analysis was done on all breast FNABs from 2016 through 2020. The cases were categorised according to the IAC Yokohama System. Histopathological correlation of the BI-RADS and IAC Yokohama System was performed. The rate of malignancy (ROM) for each category of the BI-RADS and IAC Yokohama System was calculated. The ROM values for categories I to V were 38%, 0.6%, 21.9%, 100%, and 97%, respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of FNAB with category III assumed as malignant were 98.9%, 85%, 76.1%, 99.3%, and 89.5%, respectively. With category III assumed as benign, these indices were 90.8%, 98.9%, 97.5%, 95.7%, and 96.2%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of BI-RADS were 91.5%, 81.9%, 72%, 95%, and 85.1%, respectively. FNAB is still an indispensable test in the evaluation of breast lesions. The utilisation of the IAC Yokohama reporting system for breast cytology in conjunction with ACR BI-RADS aids in better stratification of lesions.

Background: Breast cancer is the leading cause of cancer deaths among women worldwide. Fine needle aspiration cytology (FNAC) and breast ultrasound are pivotal in characterization of a breast lump as benign and malignant lesion. The main objectives were to categorise the Breast FNAC samples according to new system of reporting and to assess the Risk of malignancy (ROM), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy for all categories. Methods: A Total of 900 FNAB cytology specimens from January 2017 to December 2018 were obtained. These were reclassified according to newly proposed IAC Yokohama system of reporting. The ROM, sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and diagnostic yield of Breast FNAC and also of ultrasound were calculated. Result: Among 900 cases, 4.3% fall in category 1, 58%- category 2, 17.7%- category 3, 7.2%- category 4 and 12.8% - category 5, and correlated with corresponding radiological impression. Sensitivity, specificity, PPV, NPV and diagnostic accuracy of ultrasound were respectively 91.6%, 96.8%, 95.6%, 92.8%, 91.5% and those of FNAC respectively 94.59%, 98.9%, 98.59%, 95.74%, 96.97%. ROM is 5.0% for category 1, 1.2% for category 2, 12.5% for category 3, 93.65% for category 4 and 100% for category 5. Conclusion: IAC Yokohama system of reporting breast cytopathology serves as a common language to pathologist and clinician. Breast ultrasound is a non-invasive imaging-based technique and both these diagnostic tools can complement each other for patient diagnosis and management.

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.

Fine needle aspiration biopsy (FNAB), accompanied by classification systems for cytology, can offer a cheap and convenient option for the diagnosis of breast cancer in women with suspicious breast lumps. In this study, we aimed to assess the accuracy of the International Academy of Cytology (IAC) Yokohama system in a Vietnamese oncology centre. A retrospective cross-sectional study was conducted from November 2021 to April 2022 at Vietnam National Cancer Hospital. We included patients with full hospital records regarding breast lesions for which FNAB was indicated. A total of 803 patients' FNAB specimens were assessed according to the IAC Yokohama system. The basic characteristics were summarised using the appropriate summary measurements. The risk of malignancy (ROM) was calculated for each classification category. The median age was 42.7 years (range: 14-85). The mean size of the lesions was 17.9 mm (range: 4-123 mm). We had 215 histopathological reports. The most common benign and malignant diagnoses were fibroadenoma and invasive carcinoma, respectively. The ROM for categories II, III, IV, and V was calculated as 3.4%, 37.5%, 95%, and 99.2% respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 96.4%, 97.2%, 98.5%, and 93.2%, respectively. The IAC Yokohama system offers a good option with which to predict underlying breast pathology using a simple and cheap procedure. However, pathologists require continuous training to ensure accurate interpretation of the slides.

Breast cancer is the leading cause of cancer deaths among women worldwide. Fine needle aspiration cytology (FNAC) and breast sonography have played a pivotal role in the characterization of a breast lump. The main objective of this study was to analyze the correlation between the International Academy of Cytology (IAC) Yokohama for Reporting Breast Fine Needle Aspiration Biopsies (FNAB) and breast imaging reporting and data system (BIRADS) for sonography along with histopathological correlation. A total of 135 FNAC specimens were categorized according to the IAC Yokohama system and BIRADS reporting system and their correlation with histopathology wherever possible to calculate the risk of malignancy (ROM). According to IAC Yokohama categorization, the cases in categories I, II, III, IV, and V were 1,78,8,6 and 42, respectively. Akin to cytology, most of the cases were assigned BIRADS score two followed by score 6, with the Pearson's correlation coefficient between the IAC Yokohama system for reporting breast cytology and BIRADS scoring system of 1.957 with a P-value < 0.001 (strong correlation). The sensitivity, specificity, PPV, NPV, and DA of FNAC with category III assumed as malignant were 98.9%, 85%, 76.1%, 99.3%, and 89.5%, respectively. Histopathological correlation was available for 90 cases. The ROM for categories II, III, IV, and V was 5.6%,37.5%,100%, and 100%, respectively. IAC Yokohama system of reporting breast cytopathology and BIRADS serves as a common language of communication between pathologists and clinicians and aid in better stratification of the lesions. Both FNAC (minimally invasive) and ultrasound (non-invasive imaging technique) are diagnostic tools that complement each other for patient diagnosis and management.

Background: Benign and malignant lesions of breast are one of the most common causes of palpable masses seen in women. Fine-needle aspiration cytology (FNAC) is the important modality of diagnosis of breast lumps. Previously, there were no uniform criteria for reporting breast FNAC. To overcome this problem, the newly designed system – International Academy of Cytology (IAC) – Yokohama system of reporting was implemented in 2016. The system offers a structured report to the patient. Aims and Objectives: This study aims to categorize breast FNAC according to the IAC – Yokohama system of reporting, to calculate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the test, and to analyze the cytomorphological spectrum of various breast lesions. Materials and Methods: A total of 210 patients presenting with breast lump in cytology section were subjected to FNAC using a 22 gauge needle under all aseptic precautions. Detailed clinical history was taken. All cytology and histopathology examination slides (wherever available) were thoroughly studied. FNAC smears were reported using IAC – Yokohama system of reporting. Results: In our study, benign category (C2) was most commonly seen in 73.33% of cases, followed by 10.48% of cases of atypical probably benign (C3), 2.38% of cases were reported as suspicious (C4), and 11.43% of cases were reported as malignant (C5). Cytohistopathological concordance was seen in 38 cases (88.4%) whereas five cases were reported as discordant. Sensitivity and specificity of the test for the diagnosis of malignancy were 81% and 100%, respectively. PPV was 100%. NPV was 90.90%. Diagnostic accuracy of the test was 93.47%. Conclusion: The newer IAC – Yokohama system of reporting of breast FNAC is simple, has clear diagnostic criteria hence boost up the confidence as well has uniformity of reporting by cytopathologist, and increases the understanding and uniformity in assessment by the attending clinician which help in improving the communication between the pathologist and the treating clinician.

Background: Benign and malignant lesions of breast are one of the most common causes of palpable masses seen in women. Fine-needle aspiration cytology (FNAC) is the important modality of diagnosis of breast lumps. Previously, there were no uniform criteria for reporting breast FNAC. To overcome this problem, the newly designed system – International Academy of Cytology (IAC) – Yokohama system of reporting was implemented in 2016. The system offers a structured report to the patient. Aims and Objectives: This study aims to categorize breast FNAC according to the IAC – Yokohama system of reporting, to calculate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the test, and to analyze the cytomorphological spectrum of various breast lesions. Materials and Methods: A total of 210 patients presenting with breast lump in cytology section were subjected to FNAC using a 22 gauge needle under all aseptic precautions. Detailed clinical history was taken. All cytology and histopathology examination slides (wherever available) were thoroughly studied. FNAC smears were reported using IAC – Yokohama system of reporting. Results: In our study, benign category (C2) was most commonly seen in 73.33% of cases, followed by 10.48% of cases of atypical probably benign (C3), 2.38% of cases were reported as suspicious (C4), and 11.43% of cases were reported as malignant (C5). Cytohistopathological concordance was seen in 38 cases (88.4%) whereas five cases were reported as discordant. Sensitivity and specificity of the test for the diagnosis of malignancy were 81% and 100%, respectively. PPV was 100%. NPV was 90.90%. Diagnostic accuracy of the test was 93.47%. Conclusion: The newer IAC – Yokohama system of reporting of breast FNAC is simple, has clear diagnostic criteria hence boost up the confidence as well has uniformity of reporting by cytopathologist, and increases the understanding and uniformity in assessment by the attending clinician which help in improving the communication between the pathologist and the treating clinician.

Background and Objective: The International Academy of Cytology (IAC) Yokohama system for reporting breast fine-needle aspiration biopsy (FNAB) cytopathology has been proposed to standardize breast FNAB reporting. The aim of this study was to categorize breast FNAB cases performed by palpation without radiological guidance according to the IAC system, establish the risk of malignancy (ROM) for the categories and assess the system’s utility, pitfalls, and implications in low-resource/financial constraint settings. Methods: A retrospective analysis of palpation-guided FNAB of breast lesions performed without radiological guidance between January 2016 and December 2019 was carried out and was correlated with follow-up biopsies wherever available. A total of 1,089 cases were recategorized using the IAC Yokohama system. Histopathology follow-up was available for 400 cases. The data were analysed for ROM, positive predictive value (PPV), and negative predictive value (NPV). Results and Discussion: Out of 1,089 cases, 4.3% (n = 47) cases were categorized as insufficient, 82% (n = 893) as benign, 2.8% (n = 31) as atypical, 2.7% (n = 29) as suspicious of malignancy, and 8.2% (n = 89) as malignant. Some 400 cases had a follow-up biopsy, based on which, the ROM for the categories were 33.3%, 0.4%, 37.5%, 96%, and 100%. The NPV for the benign category was 99.6%. The PPV of the malignant category was 100%, that of combined suspicious of malignancy and malignant categories was 99%, and of combined atypical, suspicious of malignancy, and malignant was 90.6%. Conclusion: The IAC Yokohama system is useful in standardizing the reporting of cytopathology of breast lesions. FNAB with radiological guidance is ideal but in cases of finance/resource constraints, FNAB by palpation alone is satisfactory if the test result is in the benign, suspicious of malignancy, or malignant categories, which constitute 91.5% of the cases in this study. A repeat ultrasound-guided FNAB and/or core needle biopsy should be recommended for cases in the insufficient/inadequate or atypical categories.

BackgroundThe International Academy of Cytology (I.A.C.) Yokohama System to report breast cytopathology can effectively categorize breast diseases into different cytological groups. Fine needle aspiration (FNAC) from the lesions in the breast has been regarded as a major method of diagnosing breast cancer, particularly in rural settings. The major purpose of this study was to validate the diagnostic accuracy of breast FNA utilizing the IAC Yokohama system in future endurances. Histopathological examination is considered the gold standard for diagnosing benign as well as malignant breast lesions and is compared with FNA results.Material and methodsResearch on patients getting a core-needle, incisional, or excisional biopsy of breast lesions between January 1st, 2021, and December 31st, 2021, was conducted at a tertiary care center in central India. 216 breast FNAs were recorded utilizing the IAC Yokohama system, and the most appropriate category was assigned for every case and correlated with histopathology to evaluate the effectiveness of IAC system.ResultsThe new "International Academy of Cytology (IAC) Yokohama system" was used to categorize 216 patients into five categories based on the cytologic diagnosis.Those were C1: insufficient material (8.7%), C2: benign (65.7%), C3: atypical (1.8%), C4: suspicious of malignancy (2.7%), and C5: malignant (20.8%). FNACs were associated with ancillary testing and histological diagnosis to examine diagnostic accuracy. The overall Specificity, sensitivity, negative predictive value, positive predictive value, and accuracy were calculated with the risk of malignancy.ConclusionWith high specificity and sensitivity for each type of situation, for all tumors, and for each analyzed BI-RADS category, the IAC Yokohama system provides excellent accuracy for breast FNA .