Metastatic colorectal carcinoma and kidney tumors: a report of four cases.

AIMS AND BACKGROUND The prognosis of patients with metastatic colorectal carcinoma (CRC) has improved substantially over the last two decades. Longer patient survival comes at a price of more complications, including second primary neoplasms and metastases at unusual sites. METHOD Retrospective chart review. RESULTS We present 4 patients with metastatic CRC who developed kidney tumors. In 2 cases, partial nephrectomy or nephrectomy was performed for second primary renal cell carcinoma. The patients survived 2.5 and more than 6 years after kidney surgery. In the other 2 patients the kidney tumors were diagnosed as CRC metastases, histologically verified in one case; these two patients died within two years of diagnosis of kidney involvement. CONCLUSION The diagnostic approach to kidney tumors in CRC patients should include a biopsy because only patients with primary renal cell carcinoma and selected patients with metastatic CRC benefit from nephrectomy.