Clinical, laboratory, and pathologic findings from a case of malignant extramedullary plasmacytoma of the skin are presented. This is the 11th reported case of extramedullary plasmacytoma of the skin and the 2nd reported case with a complete follow-up and postmortem examination. In these 2 cases, surgical excision of the tumor mass, radiation therapy and chemotherapy were ineffective. At necropsy, visceral metastases were found but there was no bone marrow involvement.