The Newly proposed International Academy of Cytology (IAC) Yokohama System for Reporting Breast Fine Needle Aspiration: The Experience of a Single Institution

Objectives: (1). The newly proposed IAC Yokahama reporting system breast cytology to categorize our samples according to this classification. (2). To assess diagnostic accuracy as well as the diagnostic yield of breast FNAB with corresponding risk of malignancy (ROM) for each category and risk of onsite evaluation (REM). Materials and Methods: This is a retrospective study of breast cytology cases done at Department of Pathology. A Total of 722 FNA cytology specimens from January 2016 to December 2020 were obtained. These were studied and reclassified according to newly proposed IAC Yokohama system of reporting system of breast cytology into five categories. Results: Total of 722 cases of breast FNAC, 67(x %) were male and 655 (x %) were females. All the FNAB breast cytology smears were retrospectively reviewed and categorized according to IAC Yokohama system respectively The respective ROM for each category was 0 % for category1 (insufficient material), 3.8% for category 2 (benign), 57.% for category 3 (atypical), 46% for category 4 (suspicious for malignancy), and 99 % category 5 (malignant). Malignant cases were considered only when positive tests, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 94.9%, 99.9 %, 98.6%, 96.1%, and 98.69%, respectively. Conclusion: IAC Yokahama reporting system of breast cytology is effective to standardize the reporting in various institutes and provide clear guidelines to clinician for further management.