Plasmacytoma refers to a malignant plasma cell tumor growing within soft tissue or within the axial skeleton. There are three distinct groups of plasmacytoma defined by the International Myeloma Working Group: solitary plasmacytoma of bone (SPB), extramedullary plasmacytoma (EP) and multiple plasmacytomas that are either primary or recurrent. The most common of these is SPB, accounting for 3–5% of all plasma cell malignancies. SPBs occur as lytic lesions within the axial skeleton and extramedullary plasmacytomas most often occur in the upper respiratory tract (85%), but can occur in any soft tissue. Approximately half of all cases produce paraproteinemia. SPBs and extramedullary plasmacytomas are mostly treated with radiotherapy, but surgery is used in some cases of extramedullary plasmacy