Subcutaneous plasmacytoma metastasis precipitated by tunneled central venous catheter insertion.

Extramedullary plasmacytomas are tumors of monoclonal plasma cells arising within soft tissue that uncommonly occur in multiple myeloma patients. While sporadic development of these tumors at cutaneous trauma sites, including venous catheter access sites, has been reported, interventional radiologists seldom encounter this disease. Herein, we describe a case of metastatic subcutaneous plasmacytoma precipitated by tunneled central venous catheter insertion in a male patient undergoing stem cell therapy for treatment of multiple myeloma. In addition, we review the identification, diagnostic pitfalls, pathogenesis, and treatment of this rare entity.