Refractory plasmablastic type myeloma with multiple extramedullary plasmacytomas and massive myelomatous effusion: remarkable response with a combination of thalidomide and dexamethasone.

A 74-year-old man with multiple myeloma was refractory to melphalan/prednisolone (MP), high-dose dexamethasone and VAD chemotherapy. He had the following poor prognostic factors: 1) multiple extramedullary plasmacytomas, 2) massive myelomatous effusion, 3) increasing immature myeloma cells with plasmablastic morphology, and 4) predominance of MPC1-CD49e-CD45+ phenotype immature myeloma cells. Combination therapy with thalidomide and dexamethasone resulted in a rapid response and a partial remission despite his multiple poor prognostic factors. The present case suggests that combination therapy with thalidomide and dexamethasone is still an alternative treatment regimen for resistant extramedullary plasmacytoma with a plasmablastic morphology.