Solitary extramedullary and bone plasmacytomas versus multiple myeloma with extramedullary manifestation.

Extramedullary disease in plasma cell disorders can occur as a solitary plasmacytoma or can involve multiple sites with vastly different clinical outcomes. The article by Khaliq et al reports an unusual case of solitary extramedullary plasmacytoma (SEP) of the bladder in which the patient had a favorable outcome with lenalidomide/dexamethasone after failing first-line treatment with radiotherapy. In this context it is interesting to compare clinical outcomes of this entity to two other clinical variants of myeloma: solitary plasmacytoma of bone (SPB), and multiple myeloma with extramedullary plasmacytomas (MM/EP).