[A case report of spontaneous rupture of renal cell carcinoma difficult to be distinguished from angiomyolipoma].

A 56-year-old woman was admitted with right flank pain as the chief complaint without any trauma. Abdominal and chest computed tomography (CT scan) demonstrated with low-density area in a retroperitoneal hematoma suspected of spontaneous rupture of angiomyolipoma and hematothorax. Superselective transarterial embolization and drainage of the thoracic cavity were performed. Three months later a right renal tumor in perirenal hematoma was revealed by abdominal CT scan and suspected renal cell carcinoma. Right nephrectomy was performed. Histopathology revealed renal cell carcinoma. Including this case, 31 cases of spontaneous rupture of renal cell carcinoma have been reported in the Japanese literature.