Severely atypical changes in renal epithelium in biopsy and graft nephrectomy specimens in two cases of cadaver renal transplantation.

Severely atypical metaplastic and dysplastic changes were noted in the lining epithelium of collecting tubules and pelvis of the graft kidneys in two cases of cadaver renal transplants on immunosuppressive treatment with azathioprine and prednisolone. These changes were observed in case 1 in a needle biopsy and a nephrectomy specimen, 3 and 3.5 years after transplantation respectively. In a second case, the patient received two cadaver grafts, and both transplants showed similar changes 2 years after transplantation. The risk of malignant disease in kidney transplant recipients is now well recognized. The implications of the severe dysplastic changes noted in these two cases are discussed.