Comparison of the modified Masood's scoring index versus international academy of cytology Yokohama system in the categorization of breast fine needle aspirates.

CONTEXT: The Modified Masood Scoring Index (MMSI) categorizes breast fine needle aspirates into four categories non-proliferative breast diseases (PBD), PBD without atypia, PBD with atypia and carcinoma in situ/carcinoma. The International Academy of Cytology Yokohama System classifies the aspirates into five categories - inadequate, benign, atypical, suspicious, and malignant. Very few studies have been conducted so far to compare the diagnostic accuracy of this system. AIMS: The objectives of the study were to classify breast fine needle aspirates according to the MMSI and IAC Yokohama and assess their risk of malignancy (ROM) and performance parameters. MATERIALS AND METHODS: All breast FNAs received from June 2020 to May 2023 were classified according to the MMSI and IAC Yokohama. Using histopathological diagnosis as the gold standard, ROM and performance parameters were calculated. RESULTS: Out of the 559 breast fine needle aspirates, the histopathological correlation was available for 337 cases. The ROM for non-PBD, PBD without atypia, PBD with atypia and carcinoma in situ/carcinoma categories were 0%, 1.2%, 9.1% and 93%, respectively. The ROM for each of the categories of Yokohama system was 16.6%, 1.1%, 4.3%, 86.2% and 97.6%, respectively. The values for the sensitivity, specificity, PPV, NPV and diagnostic accuracy were slightly higher for IAC Yokohama (97.3%, 97.2%, 94.7%, 98.6% and 97.2%, respectively) than the MMSI (96.4%, 96.2%, 93%, 98.1% and 96.3%, respectively). Furthermore, another shortfall of MMSI is the inability to compare the Inadequate category of the Yokohama system. CONCLUSION: Overall Yokohama system proved to be a better system for categorizing breast lesions on FNAB as the scoring system provides more objective categorization and minimizes false positive and false negative cases.

Overcoming Pitfalls in Breast Fine-Needle Aspiration Cytology: A Practical Review.

BACKGROUND: Fine-needle aspiration cytology (FNAC) is a cornerstone technique for the initial assessment of breast lesions, offering a rapid and minimally invasive option for cytological evaluation. While FNACs can forego the need for core needle biopsies (CNBs), variations in technique, subjective interpretation, and intrinsic limitations present diagnostic challenges. The International Academy of Cytology (IAC) established the Yokohama system and is developing the WHO Reporting System for Breast Cytopathology jointly with IARC, to standardize diagnostic criteria, aiming to enhance diagnostic precision and consistency. Due to the preference for CNBs, expertise in breast FNAC is low in the developed world. SUMMARY: This review assesses common pitfalls in breast cytopathology. These common and uncommon entities may easily lead to false-negative or false-positive diagnoses, due to morphological overlap or misleading clinical and radiological contexts. For instance, pauci-cellular lesions, such as lobular carcinomas, often lead to false-negative diagnoses, whereas complex sclerosing lesions, fibroadenomas, and papillary lesions may show concerning features, resulting in a false positive. The same is true for some benign inflammatory pathologies, such as steatonecrosis, and uncommon lesions, such as collagenous spherulosis. Ductal carcinoma in situ can lead to both false-negative and false-positive diagnoses, and high-grade lesions are impossible to tell apart from invasive carcinomas. These are discussed in detail. Procedural and preanalytical conditions, and the role of ancillary testing, are also briefly addressed. KEY MESSAGES: Breast FNAB is a powerful diagnostic technique, fast and minimally invasive. Even in contexts which lack expertise, this technique can be successfully adopted with a cautious approach and as long as pitfalls are kept in mind, benefiting patients and healthcare systems.

Usefulness of the Yokohama Advanced Cardiopulmonary Help Team in patients with acute respiratory distress syndrome.

Aim: To evaluate whether establishing an extracorporeal membrane oxygenation (ECMO) specialist team, termed the Yokohama Advanced Cardiopulmonary Help Team (YACHT), affected the outcomes and centralization of patients requiring ECMO in Yokohama-Yokosuka regions. Methods: This retrospective observational study included patients aged ≥18 years and treated with venovenous-ECMO for severe acute respiratory distress syndrome (ARDS) from 2014 to 2023. The primary outcome was intensive care unit (ICU) mortality. The secondary outcomes included ICU-, mechanical ventilator-, and ECMO-free days and complications during the first 28 days. Results: This study included 46 (12 without- and 34 with-YACHT) patients. Among with-YACHT patients, 24 were transferred to our hospital from other hospitals, 14 were assessed by dispatched ECMO physicians, and 9 were transferred after ECMO introduction. No without-YACHT patients were transferred from other hospitals. With-YACHT patients experienced coronavirus disease 2019-associated respiratory failure more frequently (0 vs. 27, p < 0.001) and had higher Acute Physiology and Chronic Health Evaluation II scores (19 vs. 24, p = 0.037) and lower Respiratory Extracorporeal Membrane Oxygenation Survival Prediction scores (4 vs. 2, p = 0.021). ICU mortality was not significantly different between the groups (2 vs. 4, p = 0.67). ICU- (14 vs. 9, p = 0.10), ventilator- (11 vs. 5, p = 0.01), and ECMO-free days (20 vs. 14, p = 0.038) were higher before YACHT establishment. The incidences of complications were not significantly different between the groups. Conclusions: Mortality was not significantly different pre- and post-YACHT establishment; however, it helped promote regionalization and centralization in Yokohama-Yokosuka areas. We will collect more cases to demonstrate YACHT's usefulness.

Assessing the accuracy of the International Academy of Cytology Yokohama System for reporting breast fine needle aspiration biopsy cytology at a Vietnamese oncology centre.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Systematic Review and Meta-Analysis of the Diagnostic Accuracy of the International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy in Diagnosing Breast Cancer.

OBJECTIVES: The primary objective is to determine the accuracy of fine-needle aspiration biopsy (FNAB) in breast lesions reported according to the International Academy of Cytology (IAC) Yokohama system for reporting breast FNAB. The participants include any patient presenting with any breast lesion found suitable for FNAB. The target condition was breast cancer. The secondary objective was to study the proportion of inadequate FNAB in the selected studies. METHODS: PubMed/MEDLINE and Embase were searched for studies having all the following key search terms: Breast AND FNAB AND Diagnostic Accuracy published in the time frame of 2017 to May 16, 2022. The Cochrane and PROSPERO databases, citations of selected articles and articles citing the selected articles were also searched. Studies assessing the diagnostic accuracy of breast FNAB in diagnosing breast cancer, which had at least 75 subjects (and at least 20 subjects each in the benign and malignant FNAB groups), were selected. The reference standard was histopathology (or adequate clinical follow-up for benign disease). Studies were screened independently by two researchers, with a consensus reached among the authors in cases of conflict. The risk of bias and applicability were assessed using the QUADAS-2 tool. Sensitivity and specificity at each diagnostic cut-off were assessed by bivariate generalized linear mixed-model meta-analysis. The area under the receiver operating characteristics curve (AUC) and inadequacy rate were assessed by random-effects meta-analysis. The confidence intervals of sensitivity, specificity, and AUC were examined against a value of 0.95. RESULTS: Twenty-two studies, all of which were cross-sectional single-gate studies, were selected with a total of 10,886 subjects with a primary breast lesion having concurrent FNAB and reference standard reports. Sensitivity and specificity, with 95% confidence intervals, were 0.978 [0.968, 0.985] and 0.832 [0.76, 0.886] for the diagnostic cut-off of "Atypical considered positive for malignancy," 0.916 [0.892, 0.935] and 0.983 [0.97, 0.99] for the cut-off of "Suspicious of Malignancy considered positive," and 0.763 [0.706, 0.812] and 0.999 [0.994, 1] for the cut-off of "Malignant considered positive." The overall AUC was 0.975 [0.962, 0.984]. FNAB sampling without imaging guidance was associated with lower inadequacy. DISCUSSION: There is strong evidence that the overall accuracy, sensitivity for "Atypical category considered positive" and specificity when "Suspicious or Malignant categories are considered positive" of FNAB are high when using the categories of the IAC Yokohama Reporting System, demonstrating the usefulness of FNAB in diagnosing breast cancer.

Risk of Malignancy in Breast FNAB Categories, Classified According to the Newly Proposed International Academy of Cytology (IAC) Yokohama System.

Background: A new category system comprising five classes (C1-insufficient material, C2-benign, C3-atypical, C4-suspicious, and C5-malignant) has been proposed by the International Academy of Cytology (IAC) for fine needle aspiration biopsy cytology (FNAB) for proper diagnosis of breast cancer. Aims and Objectives: This study is designed to categorize institutional FNAB data according to the new system and calculation of the absolute risk of malignancy (ROM), sensitivity, specificity, positive predictive values, false negative and false-positive rate. Study Design: We conducted a retrospective cross-sectional study involving 2133 cases collected between June, 2008 and August, 2019, at Foundation University Medical College's Department of Histopathology and the Surgery and Oncology Department at the Fauji Foundation Hospital. All cases fulfilling the inclusion and exclusion criteria were retrieved from the archives and reviewed by two expert pathologists. Matching histopathology was compared with the cytology reports for concordance or discordance of results. Findings: We found 6.9% (n = 147) insufficient, 65.8% (n = 1403) benign, 7.2% (n = 153) atypical, 7.5% (n = 160) suspicious and 12.6% (n = 270) malignant cases. Cyto-histological correlation was found in 421 cases from the year 2014 to 2019 with 370 concordant and 51 discordant cases. The maximum number of concordant cases was 151 in the C5 category and discordant cases had a diagnosis of C3 and C4 on cytology with 16 cases in each category. The calculated values of ROM were 45.45%, 10.3%, 30.6%, 82.79% and 99.34% from C1 to C5, respectively. We calculated 83.42% absolute sensitivity and 85.24% specificity. The positive predictive value for category 3, 4 and 5 was 67.34%, 82.7% and 99.34%, respectively, while false-negative rate was 7.9% and false-positive rate was 0.66%. Conclusion: The ROM for C1 category calculated from this study is quite high (45.45%) compared to previous studies; therefore, it is recommended to perform core needle biopsy in all these cases. The higher sensitivity and specificity of this method of diagnosing malignant lesions supports its use.

The role of the IAC Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy and the ACR Breast Imaging-Reporting and Data System in the evaluation of breast lesions.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Application of immunocytochemical and molecular analysis of six genes in liquid-based endometrial cytology.

BACKGROUND: The Yokohama System of Endometrial Cytology has been used for reporting endometrial cytology, which includes gray zone category, atypical endometrial cells (ATEC), subdivided into ATEC-US and ATEC-AE. ATEC-US has been reported to be correlated with malignancy in nearly 10% of the cases. For accurate diagnosis, application of ancillary techniques on endometrial cytology was investigated. METHODS: Thirty-seven liquid based cytological specimens (SurePath™) with diagnosis of ATEC or malignant which have corresponding histological specimens, were subjected to immunocytochemical analysis for ß-catenin, ARID1A, and PTEN. Hot spots of mutations for KRAS, BRAF and PIK3CA were evaluated by using i-densy system (ARKRAY). RESULTS: In endometrial samples with the diagnosis of ATEC and malignant, aberrant gene expressions and/or gene mutations for ß-catenin, ARID1A, PTEN, KRAS, BRAF, and PIK3CA were observed in 32.4, 18.9, 37.8, 18.8, 0, and 37.1%, respectively. When any of the genes had aberrant expression or mutation, only sensitivity was better than that of cytology (77 vs. 53.8%). However, specificity, positive predictive value, negative predictive value, and accuracy was better in cytology than those of ancillary techniques. Increasing rate of abnormality according to the consequent histology results was observed in ARID1A (p = .015). Frequent loss of PTEN immunostaining (45.8%) and PIK3CA mutation (43.5%) was observed in the cases with consequent benign histology results. CONCLUSION: In ATEC category of endometrial cytology, gene expression and mutation analysis of six genes were insufficient to aid conventional cytological diagnoses albeit increased sensitivity. Further investigation would be necessary.

Reproducibility of the "International Academy of Cytology Yokohama System for Reporting Breast Cytology" - A Retrospective Analysis of 70 Cases.

Background: Fine-needle aspiration cytology (FNAC) is the most practiced initial method for evaluation of breast lesions. The International Academy of Cytology Yokohama System for Reporting Breast (IAC YSRB) Fine-Needle Aspiration Biopsy Cytopathology has been developed to standardize the reporting system. However, literature available on the inter-observer reproducibility of 5 IAC YSRB categories is limited. Aim: We investigated the inter-observer reproducibility of the IAC YSRB system. Method and Materials: A total of 70 consecutive specimens obtained from FNAC of breast lesions were reviewed retrospectively by 3 experienced cytopathologists who allotted 1 to 5 IAC YSRB categories. Results: The percent overall agreement between observers was 70.48% and the free marginal kappa was 0.63, which signifies substantial agreement. After combining "Suspicious" and "Malignant" categories, overall agreement was 80.95% and free marginal kappa became 0.75. Conclusions: Inter-observer agreement of three (70.48%) cytopathologists was substantial. Agreement can be improved by combining certain categories, especially "Suspicious" and "Malignant". Technical quality limitation plays a significant role in a proportion of cases, mainly the "Atypical" and "Suspicious of malignancy" categories. Application of the IAC YSRB system in day-to-day practice will increase the inter-observer agreement.

Usefulness of Fractal Analysis of Kirsch Edge Images for the Tissue Fragment Inner Structure in Breast FNAB.

OBJECTIVE: Recent advances in high-precision mammography and ultrasound screening have led to an increase in the detection of early lesions (ductal carcinoma in situ and small cancers) appearing as microcalcified lesions or microcystic images, and there needs to be an improvement in the accuracy of breast fine-needle aspiration biopsy (FNAB) assessing these lesions. The objective of this study was to investigate whether fractal analysis of Kirsch edge images for the tissue fragment inner structure (FKT) is useful in breast FNAB. FKT measures tissue fragment chromasia of hyperchromatic crowded tissue fragments (HCG), tissue fragment shape unevenness, and tissue fragment inner structure complexity. Study Design Materials: Nineteen epithelial tissue fragments of fibroadenoma (FA) from 7 patients and 52 tissue fragments of invasive breast carcinoma of no special type (IBC-NST) (grade 1-2) from 11 patients were assessed. First, tissue fragments were classified into small (smaller than 60 × 102 µm2), medium, and large (100 × 102 µm2 or larger), and the appearance rate of each size was determined. Second, for FKT, the luminance value of tissue fragment chromasia, the unevenness and fractal value, and the tissue fragment inner structure complexity were determined. In statistical analysis, the Steel-Dwass test, nonlinear discriminant analysis, and receiver operating characteristic analysis were performed, setting the significance level at p < 0.05. RESULTS: "Unevenness of the tissue fragment shape," "fractal value of the tissue fragment shape," and "fractal value of the tissue fragment inner structure" were significantly higher in small and large tissue fragments in IBC-NST compared with those in FA. The specificity and sensitivity were the highest (100%) in small tissue fragments in multivariate analysis using 4 variables ("luminance value of tissue fragment chromasia," "unevenness of tissue fragment shape," "fractal value of the tissue fragment shape," and "fractal value of the tissue fragment inner structure"). CONCLUSION: FKT, which evaluates "tissue fragment darkness," "tissue fragment shape unevenness," and "tissue fragment inner structure complexity" focusing on small tissue fragments of HCG in breast FNAB, is useful as a system that assists cytopathological assessment of breast FNAB.

Categorization of Breast Fine Needle Aspirates Using the International Academy of Cytology Yokohama System Along with Assessment of Risk of Malignancy and Diagnostic Accuracy in a Tertiary Care Centre.

CONTEXT: The International Academy of Cytology Yokohama System has developed a standardized system of reporting breast cytology by classifying them into five categories - insufficient, benign, atypical, suspicious, and malignant. Numerous studies conducted at different centers are required to confirm the risk of malignancy of the different categories. AIMS: The main objectives of our study were to classify breast fine needle aspirates according to the IAC Yokohama system and assess the risk of malignancy, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. SETTINGS AND DESIGN: It was a retrospective study done over a period of 2 years from January 2018 to December 2020. MATERIALS AND METHODS: All breast FNAs done in the above period were retrieved and classified into five categories according to the Yokohama system. Histopathological diagnosis was also retrieved wherever available. STATISTICAL ANALYSIS USED: Using a histopathological diagnosis as the gold standard, sensitivity, specificity, PPV, NPV, and diagnostic accuracy were calculated. For each of the five categories, the risk of malignancy was also assessed. RESULTS: Out of the 554 breast fine needle aspirates, 242 had histopathological correlation. The risk of malignancy for insufficient, benign, atypical, suspicious, and malignant categories were 5%, 1.5%, 17.4%, 81.8%, and 100%, respectively. Maximum sensitivity (97.2%) was achieved when atypical, suspicious, and malignant cases were considered as positive test results. The highest specificity (100%) was observed when only malignant cases were considered as positive test results, whereas maximum diagnostic accuracy (96.4%) was noted when the malignant and suspicious category was included in positive test results. CONCLUSION: The IAC Yokohama system is an excellent system for accurately diagnosing breast fine needle aspirates with greater reproducibility of reports and better communication between the pathologist and clinician.

Fine-Needle Aspiration Biopsy Cytopathology of Breast Lesions Using the International Academy of Cytology Yokohama System and Rapid On-Site Evaluation: A Single-Institute Experience.

INTRODUCTION: Breast cancer is rapidly emerging as the leading cause of cancer in Indian women. Robust cytopathology and histopathology services are required to tackle this growing burden. The use of rapid on-site evaluation (ROSE) and the International Academy of Cytology (IAC) Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy (FNAB) Cytopathology, which offers structured protocols, are expected to improve breast cytopathology reporting. METHODS: We retrieved the cytopathology slides, categorized them by the IAC Yokohama System and histopathology data of all the patients who had been investigated for breast lesions from September 2016 to December 2018, and compared the cytopathology and histopathology. Risk of malignancy (ROM) and performance metrics, like sensitivity, specificity, predictive values, accuracy, and area under the curve were computed. RESULTS: A total of 1,147 FNABs were evaluated, of which 442 (38.5%) underwent ROSE and 624 (54.4%) histopathology. Reported using IAC categories, our cohort recorded 4.9% inadequate, 65.3% benign, 7.8% atypical, 3.3% suspicious for malignancy, and 18.7% malignant lesions. The overall sensitivity and specificity for identifying in situ and malignant lesions were 99.1% and 99.3%, respectively, and were substantially improved by ROSE. ROSE improved the concordance between cytopathology and histopathology from 76.9% to 90.2%, by reducing inadequate (p < 0.001) cases. The ROM increased along a gradient from inadequate to malignant categories, with the gradient being sharpened by ROSE. The false negativity rate was 0.7% and false positivity rate 0%. CONCLUSION: Incorporating ROSE and the IAC Yokohama System for breast cytopathology reporting improves accurate diagnosis of breast lesions, prevents missed diagnoses, and provides reliable estimates of ROM. These protocols also aid in standardizing a reproducible system for monitoring and auditing of breast pathology services, identify areas that need strengthening, and improve training at pathology centers.

Risk Stratification of Breast Fine-Needle Aspiration Biopsy Specimens Performed without Radiologic Guidance by Application of the International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Cytopathology.

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.

A retrospective analysis of 512 cases of breast fine needle aspiration cytology utilizing the recently proposed IAC Yokohama system for reporting breast cytopathology.

BACKGROUND: Recently the International Academy of Cytology (IAC) introduced a new reporting system for breast fine-needle aspiration cytology that classifies cytologic diagnoses into five-categories: (I) insufficient material, (II) benign, (III) atypical, (IV) suspicious of malignancy, and (V) malignant. The current study was undertaken to categorize the breast lesions utilizing the newly proposed IAC Yokohama classification system and evaluate the risk of malignancy (ROM) for respective categories and the diagnostic yield of this technique. METHODS: All FNAs of breast lesions over 2.5 years were categorized retrospectively using the newly proposed IAC Yokohama reporting system. The ROM was calculated along with sensitivity, specificity, positive and negative predictive value, diagnostic accuracy, false positive, and false-negative rate using the histological diagnosis as the gold standard. RESULTS: The 512 cases were distributed as follows: Category I (insufficient material) 7.4%, Category II (benign) 74%, Category III (atypical) 5.7%, Category IV(suspicious) 1.4%, and Category V (malignant) 11.5%. Histopathological correlation was available in 285 (55.7%) cases. The respective ROM calculated was 33.3%, 0.5%, 13.3%, 83.3%, and 100% for Category I-V. The Sensitivity, Specificity, Positive and Negative Predictive Value, and Diagnostic accuracy were 95%, 99.5%, 98.27%, 98.6, and 98.5% respectively. CONCLUSIONS: Despite previous attempts to establish a standardized diagnostic terminology, there has been a lack of a single internationally approved standardized reporting system allowing substantial diagnostic clarity and incorporating distinct diagnostic categories, each linked with a specific ROM and recommended management. This System also provides enhanced communication between pathologists and attending clinicians for the benefit of the patient.

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.

Accuracy of Breast Fine-Needle Aspiration Biopsy Using the International Academy of Cytology Yokohama System in Clinico-Radiologically Indeterminate Lesions: Initial Findings Demonstrating Value in Lesions of Low Suspicion of Malignancy.

BACKGROUND: Fine-needle aspiration biopsy (FNAB) in breast lesions offers accurate results in differentiating benign and malignant lesions. However, its role is unclear when core-needle biopsy (CNB) is available, the latter providing additional information regarding tumor grade, invasion, and hormone receptor status in malignant lesions. In benign breast lesions, especially in BIRADS category 4a and 4b, FNAB, and CNB provide similar pathological information, whereby FNAB may serve as a more rapid and cost-effective investigation. The study was planned to reevaluate the diagnostic accuracy of FNAB in BIRADS category 4a, 4b, and 4c lesions. MATERIALS AND METHODS: FNAB and biopsy reports of all patients with breast lesions sent between September 1, 2018, and November 30, 2020, were collected and the International Academy of Cytology (IAC) Yokohama category and BIRADS score were recorded for each case. The rate of malignancy and the accuracy of FNAB in diagnosing malignancy were calculated for each BIRADS 4a, 4b, and 4c subgroup. RESULTS: A total of 249 cases of BIRADS 4 lesions had corresponding cytology and histopathology diagnoses. FNAB showed high diagnostic accuracy in all BIRADS groups. A benign categorization was associated with a very low number of false-negative diagnoses, especially in BIRADS 4a lesions. CONCLUSION: The study reconfirms the excellent accuracy of breast FNAB using the IAC Yokohama system in diagnosing breast malignancies. Furthermore, BIRADS 4a lesions found to be belonging to the cytological benign category may be excluded from CRB and kept on clinical follow-up.

Prospective evaluation of accuracy of fine-needle aspiration biopsy for breast lesions using the International Academy of Cytology Yokohama System for reporting breast cytopathology.

BACKGROUND: Classification of breast lesions into different cytological groups can accurately be done using the International Academy of Cytology (IAC) Yokohama System for reporting breast cytopathology. Fine needle aspiration biopsy (FNAB) of breast lesions has been considered to be the primary investigation in detecting breast cancers, especially in low-cost settings. The main objective of this study was to prospectively re-confirm the diagnostic accuracy of breast FNAB using the IAC Yokohama system. Additionally, separate secondary subgroup analysis was done to confirm the accuracy of breast FNAB excluding lymph-node positive and lymphadenopathy positive tumors. MATERIAL AND METHODS: A prospective study was done on patients undergoing biopsy of breast lesions between September 01, 2019 and November 30, 2020 (519 biopsies on 487 unique patients). Of these 519 histopathology biopsies, 505 had corresponding FNAB report of the same site. The FNAB was reported using the IAC Yokohama system and the most suitable category was allotted in every case. The rates of malignancy for each category and the accuracy of breast FNAB in diagnosing malignancy were calculated. RESULTS: Of the total 487 patients, 120 cases were benign on histology, while 367 were malignant. The rates of malignancy in benign, atypical, suspicious and malignant categories were 5%, 25%, 71%, and 99.7%, respectively. The diagnostic accuracy of atypical, suspicious and malignant categories was calculated as 90.1%, 95.2%, and 93.3%, respectively. CONCLUSION: The high diagnostic accuracy for each BIRADS category suggest excellent accuracy for Breast FNAB using the IAC Yokohama system.

Implementation of the International Academy of Cytology Yokohama standardized reporting for breast cytopathology: An 8-year retrospective study.

BACKGROUND: The International Academy of Cytology (IAC) Yokohama reporting system was recently proposed to serve as a standardized diagnostic platform for the cytological interpretation of breast fine needle aspiration biopsy (FNAB). Five cytological categories were suggested, linked to a certain risk of malignancy (ROM). The aim of this study was to assess the potency of this newly proposed reporting guideline, with a review of literatures. METHODS: This is a retrospective study over 8-year duration in which all the breast FNABs performed in our institution were recategorized in accordance to the IAC Yokohama reporting system. Kappa coefficient was used to evaluate the agreement between the proposed cytological category and corresponding histological diagnosis, with the level of significance set at 5%. Cyto-histopathological correlation and its diagnostic performance were also assessed. RESULTS: A total of 1136 breast FNABs were analyzed, including 31 repeat FNABs. Of these, 521 (47.1%) cases had matched histopathological results. Respective ROM for each category was: "insufficient" 13.6%, "benign" 0.4%, "atypical" 25.0%, "suspicious" 85.7%, and "malignant" 100%. There was substantial agreement (κ=0.757) between cytology and histopathological results. Our data revealed a high-diagnostic specificity, sensitivity, positive and negative predictive value of 99.3% (95% CI: 97.6%-99.9%), 94.2% (95% CI: 87.9%-97.9%), 98.0% (95% CI: 92.5%-99.5%), 98.0% (95% CI: 96.1%-99.1%) respectively when both the "suspicious" and "malignant" cases were considered as positive tests, with area under the curve of 0.993. CONCLUSIONS: The IAC Yokohama system is a reliable, evidence-based, and standardized reporting system that helps to facilitate communication among cytopathologists, radiologists, and surgeons toward individualized patient management.

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

BACKGROUND: The International Academy of Cytology (IAC) Yokohama system is a recently proposed system for reporting breast cytology by fine needle aspiration biopsies (FNAB). Multiple studies are needed to confirm the risk of malignancy (ROM) of the various reporting categories of this system. The present article studies the accuracy of the IAC Yokohama system in our center. METHODS: Over a period of 1 year (September 2018-August 2019), all cases of breast masses assessed by FNAB and histological correlation were studied retrospectively. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) and overall accuracy of the IAC Yokohama system for diagnosing malignancy were assessed. The rates of malignancy (ROM) of each diagnostic category were also estimated. RESULTS: Three hundred and twenty-one FNABs had cyto-histological correlation. The percent sensitivity (with 95% Confidence Intervals) when the atypical, suspicious of malignancy and the malignant categories were regarded as positive for malignancy were 98.2% [95.5%, 99.5%], 96.0% [92.5%, 98.2%], and 86.7% [81.5%, 90.8%] respectively. The percent specificity (with 95% Confidence intervals) for the same categories in the same order were 59.5% [47.4%, 70.7%], 91.9% [83.2%, 97.0%], and 100% [95.1%, 100%] respectively. The area under curve (AUC) for diagnosing malignancy was 0.981[0.963, 0.993]. The ROM for the benign, atypical, suspicious of malignancy and malignant category were 8.3% [2.3%, 20.0%], 17.2% [5.8%, 35.8%], 77.8% [57.7%, 91.4%], and 100% [98.1%, 100%] respectively. CONCLUSION: The IAC Yokohama system is suitable for accurately reporting breast lesions on FNAB.