Metastasis of cancer to cancer: report of a case.

A case of primary, widely disseminated prostatic carcinoma causing bilateral urinary tract obstruction, hydronephrosis, and papillary necrosis and metastasizing in the substance of an unusual histologic variant of renal cell carcinoma and tubular adenoma of the same kidney is presented. Unusual incidental findings include isolated cardiac amyloidosis and myocardial abscesses. A brief review of the literature is presented. The peculiar tendency for renal cell carcinoma to be the host tumor for other primary carcinomas and various theories to account for this phenomenon are commented upon briefly.