RESUMEN
Chronic granulomatous mastitis is not an uncommon entity. It mimics breast carcinoma on physical, gross and microscopic examinations; both on histopathological and fine needle aspiration cytology. At other times invasive ductal carcinoma may suggest granulomatous mastitis. A case is presented here where ductal carcinoma was misinterpreted as granulomatous mastitis on fine needle aspiration cytology smears in a 48 yr old woman who presented with large painful lump in her left breast. The mass was subsequently excised and the histopathological examination revealed infiltrating ductal carcinoma. Reexamination of the cytology smears did show some atypical cells commensurate with the ductal carcinoma. We here discuss various reasons and factors responsible for over and under interpretation of cytological atypia