Multiple myeloma of the serosa coat.

We report on a 47-year-old male patient with IgA-kappa plasmacytoma, who 12 months subsequent to diagnosis developed marked ascites. On light and electron microscopy morphologically identical plasma cells with bizarre intracytoplasmatic material were found in the bone marrow, pleural exudate, and ascites fluid. This kind of extramedullary spread is extremely rare and usually resists therapy. The mean survival rate for the 9 patients with malignant plasmacellular ascites whose cases have been documented so far was 2 months. After progression under VCMP regimens our patient has been successfully treated over a period of more than 4 years with i.v. VP16 monotherapy with additional intermittent local administration of methotrexate and systemic poly-chemotherapy according to the VAD scheme.