A Rare Case of Extramedullary Plasmacytoma Presenting as Large Abdominal Mass.

A 79-year-old female with a past medical history of multiple myeloma, diabetes mellitus and chronic kidney disease presented to the hospital with generalized weakness. The patient was found to have a firm abdominal wall mass with no underlying skin changes or drainage on physical examination. Computerized tomography of the abdomen and pelvis without contrast revealed a large mass-like structure in the anterior abdominal wall in the subcutaneous region extending into the abdomen through the mesentery with juxtaposition and partial involvement of the left hepatic lobe and distal stomach. Solitary extramedullary plasmacytomas are extremely rare tumors that occur outside of the bone marrow in the absence of systemic involvement. This case reports details the finding of an extramedullary plasmacytomas, which accounts for less than 5% of plasma cell neoplasms.