Primary malignant lymphoma of the breast mimicking breast carcinoma: a case report.

A case of primary malignant lymphoma of the breast in a 52 year old woman is described herein. She presented with a painless tumor of the right breast, which was elastic-hard and measured 2 X 1 cm, although there was no lymphadenopathy noted in the axilla or any other regions. Both the biopsy carried out prior to surgery and frozen sections revealed evidence of malignancy, however, histologically, it was difficult to differentiate between malignant lymphoma and carcinoma until staining with the monoclonal antibody MB1 was performed. This allowed a diagnosis of B cell malignant lymphoma of the diffuse large-cell type to be made. The patient remains alive and well 24 months after her mastectomy.