Periductal mastitis in a male breast masquerading as lobular carcinoma on fine needle aspiration cytology

Fine needle aspiration cytology (FNAC) is quite successful in identifying specific benign and malignant breast lesions, but its role in the categorization of proliferative breast lesions has not been well defined. Mastitis/ breast abscess can lead to intense inflammatory response; however, its association with epithelial hyperplasia is rarely reported. At times, it may be difficult to differentiate dense lymphoplasmacytic infiltrate from non-Hodgkin's lymphoma. We present a case of periductal mastitis associated with epithelial hyperplasia, presenting as a subaerolar swelling in a male breast, which was misinterpreted as lobular carcinoma on FNAC. Diagn. Cytopathol. 2011; (C) 2011 Wiley-Liss, Inc.