International Academy of Cytology Yokohama System for Reporting Breast Cytology and the ACR Breast Imaging Reporting and Data System (BIRADS): Are they Concordant?

Background & objective: 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.

Methods: 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).

Results: 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.

Conclusion: 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.