Breast Carcinoma is one of the common malignancies among females. In the state of Chhattisgarh, there was 26 % rise in mortality in past decade. “Triple test” for diagnosis of breast lesion is essential which includes a standardized cytology reporting system like IAC Yokohama system for breast FNAC along with clinical and radiological interpretation helps in efficient management of breast lesion. OBJECTIVE: - This study aims to validate the diagnostic accuracy of breast FNAC utilizing IAC YOKOHAMA system correlating with BIRADS and histopathological diagnosis. METHODOLOGY: - 100 cases of random female patients of more than 18 years of age within the study period from August 2024 to August 2025 who presented with breast lump willing to participate and give consent for FNAC and Ultrasound were included. Cases were categorized according to IAC Yokohama system and BIRADS. Diagnostic accuracy through the sensitivity, specificity, PPV and NPV were assessed by correlating with radiological and available histopathological diagnosis and Risk of Malignancy were calculated for each category. RESULTS: Among 100 cases, 8% fall in category 1, 58%-category 2, 9%- category 3, 9%- category 4 and 16% - category 5, and correlated with corresponding radiological and histopathological impression. ROM is 28.6% for category 1, 2.4% for category 2, 50% for category 3, 100% for category 4 and 100% for category 5. CONCLUSION: Application of the IAC Yokohama system helps in better categorization and in improving the accuracy of cytopathological reporting of breast samples. Breast ultrasound is a non-invasive imaging based technique. Both these diagnostic tools can complement each other for patient diagnosis and management.

IAC- International Academy of Cytology ROM- Risk of Malignancy PPV- Positive Predictive Value NPV- Negative Predictive Value ROSE- Rapid on site Evaluation