1) To categorize the Breast Fine Needle Aspiration Biopsy (FNAB) samples according to this new system of reporting. 2) To assess the diagnostic accuracy, sensitivity and specificity of breast FNA and calculate the risk of malignancy (ROM) for each category.
Methods: This retrospective study included all patients who underwent Breast fine needle aspiration biopsy cytology (FNAB) obtained between January 2019 to December 2019 and were reclassified according to the newly proposed IAC Yokohama reporting system. Only cases for which histopathological reports were available were included in the study. The risk of malignancy (ROM) for each category was determined. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were evaluated based on a three-category approach.
Results: A total of 63 women were included in the study. The samples were distributed as follows: insufficient material 0, benign 34.9%, atypical 3.18%, suspicious for malignancy 7.9%, and malignant 53.9%. The respective ROM for each category was 0% for category 1 (insufficient material), 4.5% for category 2 (benign), 50% for category 3 (atypical), 100% for category 4 (suspicious for malignancy), and 100% for category 5 (malignant). When calculating diagnostic accuracy and predictive values where only malignant cases were considered positive tests, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 94.40%, 100%, 100%, 91.66% and 96.55%, respectively.
Conclusion: Categorization of the Breast FNAB cytology according to the newly proposed IAC Yokohama system of reporting helps pathologists in achieving diagnostic clarity and guides clinicians in appropriate patient management. IAC Yokohama system of reporting breast cytopathology can serve as a bridge between pathologists and clinicians in effective stratification of breast lesions.