Breast fine-needle aspiration cytology utilizing the International Academy of Cytology Yokohama System: One-year retrospective study in a tertiary care center in Himachal Pradesh

ABSTRACT Background: In 2016, the International Academy of Cytology (IAC) established a reporting system for breast fine-needle aspiration (FNA) cytology. This system proposed five categories in its classification: category for insufficient; category 2 for benign; category 3 for atypical, probably benign; category 4 indicating suspicious for malignancy; and category 6 for malignant. Aims and Objectives: The aim of the present study was to review and categorize the breast FNA samples according to the new system of reporting, to assess the risk of malignancy (ROM) for each category, and to assess the diagnostic yield of breast FNA biopsy (FNAB). Materials and Methods: The present retrospective study was conducted in the department of pathology, IGMC, Shimla from January 2019 to December 2019. All the samples during this period were included in the study. Results: A total of 405 breast cytology cases were included in the present study. The FNA findings were correlated with histopathology in 82 cases. The ROM for each category was 16.6% for insufficient, 3.7% for benign, 0% for atypical for malignancy, 100% for suspicious for malignancy, and 92.3% for malignant category. Conclusion: The IAC Yokohama system for reporting breast FNA cytology helps in standardizing reports and easier communication of the pathologists with treating surgeons. It offers a ROM for each category which helps during follow-up of patients. Utilizing the system in day-to-day reporting will improve diagnostic clarity and management.