We report the case of a 73-year-old man admitted to our department with a history of hematuria, right flank pain and increasing weight loss. Ultrasound and excretory urography showed a right upper pole renal mass considered at first as a heteroplastic process. These findings were subsequently confirmed by a CT scan, which also showed another neoplasm with parenchymatous density in front of the first. The patient underwent radical nephrectomy and the histologic examination showed the simultaneous presence in the same kidney of a renal adenocarcinoma, a transitional cell carcinoma and a leiomyosarcoma of the pelvis.
