Malignant lymphoma developed in two patients after renal transplantation. In both, the central nervous system was involved. Histologic study of the tumors showed that they were composed of a monomorphous proliferation of cells characterized by a large vesicular nucleus, prominent basophllic nucleolus and strongly pyroninophilic cytoplasm. The tumors thus would be classified as "diffuse large lymphoid lymphomas with pyroninophilia" or "immunoblastic sarcomas" as described in the literature. Tumor cells resembled cells observed in the paracortex of antigenically stimulated lymph nodes, cells from malignant lymphomas in mice that were antigenically stimulated and from malignant lymphomas in patients with immunodeficiency diseases or autoimmune disorders. The distinctive morphologic features of the tumors in the transplant recipients described provide further evidence that long-term antigenic stimulation may be important in their pathogenesis.
Bibliographical noteFunding Information:
From the Departments of Surgery and Pathology, University of Minnesota, Minneapolis, Minnesota 55455. This study was supported by Grant AM 13083 from the U.S. Public Health Service. Requests for reprints should be addressed to Dr. Richard L. Simmons, Box 185-Mayo Memorial Building, University of Minnesota Hospitals, Minneapolis, Minnesota 55455. Manuscript accepted January 14, 1976.