Breast lymphoma--a pathologic study of 14 cases.

Fourteen cases of malignant non-Hodgkin's lymphoma of the breast were diagnosed at the Department of Pathology, Singapore General Hospital, since 1988. All were females with an age range of 30 to 69 years. Twelve cases were B cell and 2 were T cell in immunophenotype. Of the B cell lymphomas, one was subtyped as follicular, 8 diffuse large cell (IWF) or centroblastic (Kiel) and 3 immunoblastic lymphomas. Both T cell tumours were Ki-1 positive, large cell anaplastic lymphomas. Malignant lymphoma was not clinically suspected in any patient at presentation. Histologically, 3 cases were initially diagnosed as carcinomas, one on a trucut biopsy, another during frozen section evaluation and the third was a breast excision specimen. The pathological characteristics and potential histologic problems are detailed. The rarity of the disease, lack of uniform classification and variable treatment modalities make prognostic predictions of breast lymphoma difficult.