Metanephric adenoma is a rare tumor of the kidney. So far metanephric adenomas were considered to be benign, slowly growing and non-metastasizing tumors with an excellent prognosis. Only recently two cases of metastasized metanephric adenomas were published. Therefore, diagnostic work up, therapy and follow up of this tumor have to be reassessed. We report the case of a 42 year old male with metanephric adenoma. Current literature concerning metanephric adenoma is reviewed.