Autologous bone marrow transplantation for intra-abdominal extramedullary plasmacytoma.

A patient with an extramedullary plasmacytoma of the omentum and ovaries is described. In spite of the presence of a very high concentration of paraprotein (103.5 g/l IgG k), bone marrow involvement was not demonstrated either at presentation or during the course of the disease. After debulking surgery, chemotherapy (vincristine, prednisone, and cyclophosphamide) was initiated. Although this resulted in considerable improvement, the paraproteinemia persisted. After ten courses of chemotherapy there was recurrence of the tumor with involvement of the lymph nodes in the right axilla. Chemotherapy was changed to a CHOP regimen (cyclophosphamide, adriamycin, vincristine, and prednisone), followed by autologous bone marrow transplantation with the BEAM regimen (BCNU, etoposide, cytarabine, melphalan) as conditioning therapy. The patient was still in complete remission 1 year after transplantation. This case demonstrates that an extramedullary plasmacytoma may become manifest as extensive but localized disease with high levels of paraprotein, and that autologous bone marrow transplantation as a therapeutic modality can lead to prolonged complete remission of the disease.