Association between carcinosarcoma and the transplanted kidney

Renal carcinosarcoma is a rare tumor with 12 reported cases in the world literature. To our knowledge, carcinosarcoma of a renal allograft has not been reported to date.

A multifocal urothelial carcinosarcoma of a transplanted kidney in a 49-year-old woman is described. Genomic analysis of the extracted nuclei of all the neoplastic cells showed uniformly XY genotype proving the transplant origin of the tumor.

The carcinogenic role of immunosuppressive medications in kidney-transplanted patients is reported in the literature. In this case, immunosuppression may have promoted the carcinosarcoma.

Renal transplant patients should be monitored for the development of malignancy in the allograft and elsewhere.