Leiomyosarcoma in a Renal Allograft Recipient Treated With Immunosuppressive Drugs

A highly malignant gastric leiomyosarcoma developed in a renal allograft recipient. This was the first primary malignant tumor observed in 247 patients at the Peter Bent Brigham Hospital who received immunosuppressive therapy following renal transplantation. Among the 3,614 patients listed in the Human Kidney Transplant Registry as receiving allografts, 37 primary malignant tumors have been reported. This incidence of malignancy is 4.7 times greater than expected. Examination of the therapy employed in the 37 cases suggests that azathioprine is a major factor in the development of the tumors and that prednisone may act in a subsidiary role by suppressing the cellular immune response.