Primary extramedullary plasmacytoma of the small intestine.

We report a case of primary extramedullary plasmacytoma (PEMP), IgA kappa type, with a long clinical history, in a 64-year-old Japanese woman. In this case, PEMP occurred primarily in the jejunum and then recurred in several organs, specifically the spleen and stomach, and in the subcutaneous tissue, over a period of about 16 years. However, examination of bone marrow aspirates on several occasions continued to show no plasmacytoma involvement. The patient is still living. Immunohistochemical examinations revealed monoclonal IgA kappa immunoglobulin in the cytoplasm of infiltrating plasma cells in all surgical specimens examined. Immunoelectrophoresis revealed serum M-component only when the patient had a splenic tumor. Soon after splenectomy, the serum M-component disappeared. PEMP of the small intestine is rare.