Plasmacytoma of the testis.

Extramedullary plasmacytomas of the testes are extremely rare tumors, especially when occurring in the absence of precocious or concurrent diagnosis of multiple myeloma. This is a case report of an 83-year-old man with a solitary plasmacytoma of the left testis. Immunoperoxidase studies, performed on histologic specimens after radical orchiectomy, showed a monoclonal staining of intracellular immunoglobulin for IgG-lambda type. He has been well for more than 14 months with no evidence of local recurrence or multiple myeloma.