De novo CD5-positive diffuse large B cell lymphoma solely presenting as multiple subcutaneous nodules.

Lymphomas may involve the subcutaneous tissue as a manifestation of generalized disease. However, they rarely present with multiple involvement of the subcutaneous fat tissue without other sites of the disease. We describe a patient with CD5+ diffuse large B cell lymphoma (DLBL) that was confined to the subcutaneous tissue. A 74-year-old woman with rheumatoid arthritis was admitted because of multiple subcutaneous nodules. The patient had not been treated with cytotoxic drugs or methotrexate. The biopsied specimen disclosed diffuse infiltration of large cells with a starry sky-like appearance. The cells were positive for CD5, CD19, CD20, CD25, IgM, lambda-chain, and negative for CD10, CD23 or cyclin D1. Thus a diagnosis of CD5+ DLBL was made. The patient was treated with a modified CHOP protocol and complete remission was achieved.