We evaluated the clinical features, morphology, and incidence of 18 cases of breast lymphoma over 10 years at the University of Alabama at Birmingham. Fine needle aspiration was performed in 7 of 18 patients, and tissue biopsy/resection was available for all 18 cases. Patients were 33 to 91 years old (median, 61); 17 were women and 1 was a man. Fine needle aspiration was consistent with the tissue diagnosis in 6 of the 7 cases (86%). One case was diagnosed by fine needle aspiration as atypical cells, favor benign; the biopsy revealed diffuse large B-cell lymphoma. Tissue diagnoses revealed that 11 cases (61%) represented diffuse large B-cell lymphoma and 3 (17%) were follicular lymphomas. The remaining 4 cases (22%) were plasma cell neoplasm, T-cell neoplasm, Burkitt's lymphoma, and precursor B-cell lymphoblastic lymphoma. Flow cytometry and/or gene rearrangement supported the diagnosis of lymphoma in 8 cases. Although rare, lymphoma should be considered in the differential diagnosis of a breast mass. Fine needle aspiration can facilitate appropriate triage of patients for further management. © 2006 Elsevier Inc. All rights reserved.