Atypia in fine needle aspirates of breast lesions

BackgroundThe atypical category is controversial in fine needle aspiration cytology (FNAC) of the breast; most are benign, but a significant number are malignant. To date, no morphological criterion has been found to be consistent in predicting malignancy.AimsTo evaluate specific cytological parameters and assess their usefulness in predicting histological outcome in a cohort of atypical breast FNAC, in order to establish a set of objective criteria in defining ‘high risk’ atypical breast FNAC.MethodsA retrospective review of 98 cases of atypical breast FNAC with histological correlation was undertaken. The cytological preparations were evaluated for cellularity, percentage of epithelial cell cluster and single epithelial cells, nuclear atypia, nucleus:cytoplasm ratio, percentage of bipolar nuclei, and the presence of stromal fragments, histiocytes and necrosis.Results66 of 98 cases (67.35%) showed benign histology and 32 cases (32.65%) showed malignant histology. Compared with the malignant group, the benign group had significantly lower patient age (p=0.05), higher bipolar nuclei (p