Extramedullary plasmacytoma of the gastrointestinal tract in a renal transplant recipient.

A case of gastrointestional plasmacytoma found in a renal transplant recipient is described. Immunohistochemical study using immunoglobulin-enzyme bridge technique demonstrated IgA and k-type light chains in the majority of plasma cells infiltrated in the stomach. Pathological investigation revealed multiple similar tumors in the ileum, cecum and ascending colon suggesting a plasmacytoma of multicentric gastrointestinal origin. The pathogenesis of plasma cell tumors is briefly discussed with regard to organ transplantation.