[Angiomyolipoma: a case report and a statistical study of 147 cases in Japanese literature]

A 32-year-old housewife with gross hematuria and right flank pain had excretory urography and angiography performed. A large right renal mass with neovascularity was demonstrated. Computerized tomography also revealed a large well-demarcated renal mass with low value of HU. Right nephrectomy was done and histopathological diagnosis was angiomyolipoma weighing 1100 g. A statistical study was made on 147 cases of renal angiomyolipoma in the Japanese literature including this case. The male to female ratio was 1 to 2.9, and the average age of male and female patients was 37.8 and 39.0 years, respectively. Thirty-eight per cent of the cases were associated with tuberous sclerosis. The main clinical signs were flank pain, flank mass and hematuria. In 80% of the cases, nephrectomy was done because of the difficulty of preoperative differential diagnosis from renal cell carcinoma. Recently, CT and sonography have become a great help in diagnosing angiomyolipoma, because they can demonstrate the fat in the renal mass. Conservative or surgical treatment to save the kidney can be used more often when it becomes possible to make a clear differential diagnosis between angiomyolipoma and other malignant diseases.