Prostatic adenocarcinoma (PCa) metastasizing to renal cell carcinoma (RCC) with periureteral tumor deposit: A case of tumor-to-tumor metastasis (TTM)

Abstract Renal cell carcinoma (RCC) and prostatic adenocarcinoma (PCa), occurring as a double primary is uncommon, but well documented. However, metastatic PCa in a RCC is quite rare. We report a case of an 81-year old male chemical engineer with history of hematuria and prostatomegaly suspicious for carcinoma, who underwent left radical nephrectomy for a renal mass. Histopathology revealed RCC that harbored an undiagnosed PCa. Periureteral tumor deposit likewise showed combined metastasis of RCC and PCa.