Papillary renal carcinoma arising in an ectopic native kidney and status after renal transplant: a report of a unique case and review of the literature.

Renal ectopia is an uncommon developmental defect of upper urinary tract. Except for hydronephrosis and urinary calculus formation, it is believed that ectopic kidneys are not more susceptible to diseases compared to the normally positioned kidneys. Primary renal carcinoma in ectopic kidneys is rarely observed. Our literature review identified eight cases in nontransplanted patients; seven were clear-cell carcinoma and one was papillary renal carcinoma. On the other hand, native kidneys of renal transplant patients are fifteen times more likely to develop renal carcinoma than those of nontransplanted patients. Renal malignancy has never been reported in native ectopic kidneys of transplant recipients. We report the first case of a papillary renal carcinoma in a native ectopic kidney of a 30 year-old female, six-year status after renal transplantation.