Classification of Male Breast Lesions According to the IAC Yokohama System for Reporting Breast Cytopathology

Abstract

<b><i>Objective:</i></b> This study aims to determine the diagnostic utility of the International Academy of Cytology (IAC) Yokohama System for reporting breast cytopathology in lesions of the male breast. <b><i>Study Design:</i></b> Fine-needle aspiration biopsy (FNAB) reports between 2015 and 2019 were retrospectively recategorized according to the 5-tiered IAC Yokohama Reporting System. Our database yielded a total of 1,532 FNAB reports from breast lesions, obtained from 1,350 male patients. The risk of malignancy (ROM) and diagnostic performance of FNAB were determined using follow-up histopathological diagnosis and/or clinical follow-up, where available, for each category. <b><i>Results:</i></b> The category distribution were as follows: inadequate, 40%; benign, 57%; atypical, 0.6%; suspicious for malignancy, 0.7%; and malignant, 1.6%. The ROM in each category was nondiagnostic, 11%; benign, 3%; atypical, 28%; suspicious for malignancy, 56%; and malignant, 100%. The sensitivity, specificity, positive predictive value, and negative predictive value were recorded as 63, 100, 100, and 84.6% respectively, when only malignant cases were considered as positive tests. <b><i>Conclusion:</i></b> This study validates the IAC Yokohama System for reporting male breast cytopathology. In accordance with the aim of the Yokohama System to establish best practice guidelines for reporting breast cytopathology, this comprehensive scheme facilitates comparisons between local and international institutions. The ROM acts as an internal audit for quality assurance within one’s own laboratory and provides guidance for clinical management. It highlights inefficiencies such as high inadequacy rates for category 1 and also features strengths with impressive specificity for categories 4 and 5.

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

“…The IAC Yokohama System has defined minimum criteria for adequacy and recommends the inadequate rates (category I) be less than 5%. Category I in published studies ranges from 5.7% to 40% 9‐14 . Our study reports a higher percentage of inadequate aspirates (9%) than that recommended by IAC, despite being comparable to other recently published Indian and Western studies 9‐14 …”

“…Category I in published studies ranges from 5.7% to 40% 9‐14 . Our study reports a higher percentage of inadequate aspirates (9%) than that recommended by IAC, despite being comparable to other recently published Indian and Western studies 9‐14 …”

“…Similarly the distributions of categories III, IV, and V (6.2%, 3.9%, and 14.8%) were well within the range reported in the literature (0.6%–13.74%, 0.7%–4.7%, 1.6%–28.4%; Table 7). 9‐14 …”

Informe de la citología mamaria

“…La citología puede ser utilizada para un diagnóstico preliminar en la evaluación de la mayoría de las lesiones mamarias palpables clínicamente o de aquellas impalpables detectadas por imagenología, de carácter benigno y maligno, tanto en pacientes femeninos como masculinos. El riesgo de malignidad para cada categoría, resumido aquí de estudios recientes, es como sigue: para la categoría Inadecuada/insuficiente hasta 11%; Benigna de 3% a 8,3%; Atípica de 17% a 28%; Sospechosa para malignidad de 56% a 78,8% y para la categoría Maligna entre 98,8% a 100%; observándose claramente que va aumentando, a medida que aumenta la severidad de las alteraciones cito-morfológicas [3][4][5][6].…”

The International Academy of Cytology Yokohama System for Reporting Breast Fine‐Needle Aspiration Biopsy Cytopathology: Recent research findings and the future

“…Oosthuizen et al 19 showed that the IAC system could be used to classify male breast tumors in a 5-year series of 1532 male breast FNAB cases, which yielded case distributions and ROM of 40% and 11% for the inadequate category, 57% and 3% for the benign category, 0.6% and 28% for the atypical category, 0.7% and 56% for the suspicious for malignancy category, and 1.6% and 100% for the malignant category. The sensitivity, specificity, PPV, and NPV were 63%, 100%, 100%, and 84.6%, respectively, when only malignant surgical pathology was considered positive.…”