Extramedullary plasmacytoma with gastric and lymph node involvement: an immunological study.

A case of gastric and lymph node extramedullary plasmacytoma is reported in a young Algerian female. Treatment with cyclophosphamide was ineffective, but rubidazone, followed by a maintenance therapy with prednisone, procarbazine, and vinblastine induced a complete remission. Immunofluorescence studies and biosynthesis experiments in vitro showed that the tumor cells produced and secreted IgA-kappa molecules, whereas no monoclonal immunoglobulin could be found in the serum and gastric juice.