Urinary cytology in renal transplant recipients with stable graft functions

The utility of routine urinary cytology in renal transplant recipients was investigated. Slides of 79 urine samples obtained from 59 renal transplant patients shortly after transplantation and of 275 urine sediments from 126 patients who had received a transplant before 1978 were screened for abnormal urothelial cells. None of the samples taken within one year of transplantation contained malignant cells. For five patients transplanted before 1978, repeated cytologic examinations showed malignant cells, but neither urologic examination nor clinical nor postmortem follow-up studies revealed a tumor. In all five cases, the abnormal cells disappeared from repeat samples within two to three months. None of the other 121 patients, with repeatedly normal urinary cytologies, exhibited a urinary tract carcinoma in the 24-month follow-up period. It would appear that the cytologic findings in the urine of renal transplant patients who have received long-term immunosuppressive medication may be transiently abnormal.