Fine needle aspiration cytology of atypical (C3) and suspicious (C4) categories in the breast and its histopathologic correlation

BACKGROUND: In 1996, National Cancer Institute (NCI) proposed five categories for the diagnosis of breast cytology in order to bring a degree of uniformity to the diagnostic reporting. Of these, categories 3 and 4 were sparsely studied. AIMS: The present study was undertaken for the evaluation of the fine needle aspiration cytology (FNAC) categories of C3 and C4 in the breast lump and its histopathological correlation. MATERIALS AND METHODS: In the retrospective study, a total number of 728 FNACs were categorized according to the NCI; of these, 28 cases of category C3 and 65 cases of category C4 were compared with histopathological diagnoses. RESULTS: On histopathological examination of category C3, 18 (64.3%) cases showed benign lesions and 10 (35.7%) cases showed malignancy and among the C4 category, benign lesions found in nine (13.8%) and malignancy found in 56 (86.2%) cases. There was a significant statistical difference between the number of benign and malignant diagnoses for cytological categories of C3 (64.3%) and C4 (86.2%) (P < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of C4 category in the diagnoses of malignancy were 84.8%, 66.7%, 86.2%, and 64.3%, respectively. CONCLUSION: FNAC of the breasts is a simple, cost-effective, accurate, quick, and relatively less painful procedure, and it continues to play an integral part in the management of breast lesions. Our study concluded that there was a statistically significant difference between the number of benign and malignant diagnoses for categories of C3 and C4.