Mantle cell lymphoma presenting as a breast mass

Breast lymphoma accounts for less than 1% of all non-Hodgkin's lymphomas (N HLs) and approximately 0.1% of all breast neoplasms. Most breast lymphomas are classified as diffuse large B cell or mucosa associated lymphoid tissue (MALT) lymphomas. The case of a 53 year old woman presenting with a breast mass and found to have mantle cell lymphoma is described. Core biopsy of t he breast lesion showed a B cell NHL, probably of large cell type and of hi gh grade. Morphological and immunophenotypic analysis of peripheral blood a nd bone marrow samples suggested a mantle cell lymphoma (MCL). This was con firmed by the detection of a t(11; 14) in the bone marrow aspirate and brea st tissue by polymerase chain reaction analysis. There have been no previou s reports of an MCL presenting as a breast lump. Because a diagnosis of MCL has prognostic and therapeutic implications, this case highlights the need for an awareness of MCL presenting in this way, and the requirement for sp ecialised investigations in its detection.