Multiple myeloma with extramedullary disease.

Plasmacytoma is a tumor mass consisting of atypical plasma cells. Incidence of plasmacytomas associated with multiple myeloma range from 7% to 17% at diagnosis and from 6% to 20% during the course of the disease. In both situations, occurrence of extramedullary disease has been consistently associated with a poorer prognosis of myeloma. Extramedullary relapse or progression occurs in a variety of clinical circumstances and settings, and therefore requires individualization of treatment. Alkylating agents, bortezomib, and immunomodulatory drugs, along with corticoids, have been used to treat extramedullary relapse but, because of the relatively low frequency or detection rate of extramedullary relapse, no efficacy data are available from controlled studies in this setting.