Renal cell carcinoma from a transplanted allograft: two case reports and a review of the literature.

We report 2 cases of renal cell carcinoma (RCC) in which the tumor arose from a transplanted allograft. The first case is a 52-year-old man with a failed cadaveric renal transplantation found to have metastatic RCC. The tumor was proven to be from the allograft, as fluorescence in situ hybridization analysis of biopsy material showed a female karyotype, consistent with his female donor. The second patient is a 45-year-old man who had undergone cadaveric renal transplantation in 1985 for chronic glomerulonephritis and, after 22 years, presented with renal failure. Biopsy and subsequent allograft nephrectomy revealed innumerable microscopic foci of RCC. There are only a few reported cases of RCC arising in kidney allografts and even fewer with reports of metastatic disease from the allograft. Treatments in patients with disease confined to the kidney have included partial nephrectomy and total nephrectomy. A literature search did not find any reports of treatment of metastatic RCC that arose from a renal allograft.