International Academy of Cytology Guidelines Based Categorization of Breast Fine-Needle Aspiration Cytology Lesions and their Histopathological Correlation

Abstract

Context: International academy of cytology (IAC) has established a standardized reporting system for fine-needle aspiration (FNA) cytology of breast lesions. They have introduced five categories (Code C1 to Code C5) for reporting breast cytology, each with clear descriptive term for the category, risk of malignancy (ROM) and a suggested management algorithm. Aim: Aims of the present study were to reclassify and correlate the breast FNA (IAC guidelines) with histopathological findings and to calculate the ROM for each category with special emphasis on assessing the diagnostic efficacy of cytological evaluation of code 3 and code 4. Materials and Methods: A 3 years' retrospective cross sectional study included 448 breast FNA samples that were reassessed and reclassified according to the IAC reporting system. The ROM for each category was analyzed. Results: The breast FNA samples were distributed in following categories as: C1 (insufficient material)− 1.78% (n = 8), C2 (benign) – 71.66% (n = 321), C3 (Atypical but benign) −10.81% (n = 45), C4 (Suspicious for malignancy) – 4.91% (n = 22), and C5 (Malignant)– 11.60% (n = 52). Out of the 448 cases, histopathological correlation was available for 205 cases. The ROM for each category was calculated as: 0% for C1, 2.04% for C2, 10.8% for C3, 85.71% for C4, and 100% for C5. The ability of C3 and C4 lesions to diagnose breast malignancy was statistically significant, P value 0.042 (P < 0.05). Conclusion: The IAC system for reporting of breast cytology effectively helps in accurate diagnosis and assessment of ROM for each category which helps in better patient management and further research.