Primary plasmacytoma of the testis. Case report and review of the literature.

A primary plasmacytoma of the testis is an extremely rare tumor. To date less than 10 cases have been published. Typically a firm mass of the testis or also of the epididymis is found. Histologically, infiltration can be seen with atypical plasma cells compressing the seminiferous tubuli. Immunohistochemical examination shows a PAS-positive reaction. Monoclonality can be confirmed by identification of the IgA lambda chain. Therapy of choice is the radical orchiectomy. The prognosis of primary plasmacytoma of the testis seems to be good. Nevertheless, a follow-up of some years is necessary to detect possible intramedullar manifestations.