[Renal angiomyolipoma: diagnosis and treatment]

In 10 years the diagnosis of renal angiomyolipoma (RAML) was made in 14 patients (male-to female ratio 1:3.7) at our institution; 1 case was associated with tuberous sclerosis (TS) and 1 case had regional lymph node involvement. A statistical study was done on data taken from 739 cases of RAML in the Japanese literature, including our cases. The male to female ratio was 1 to 3. Twenty eight percent of the cases were associated with TS. The ratio of bilateral cases to the unilateral one was 1 to 3. The main clinical signs were flank pain, abdominal mass, hematuria and fever elevation. Recently the ratio of nephrectomy has decreased to 30%. The percentage of detecting the fat component by ultrasonography (US), computed tomography (CT) and magnetic resonance imaging were 88.1%, 86.5% and 80.8% respectively. The percentages of visualizing hypervascularity, aneurysms, absence of arterio-venous shunt and onion peel appearance by selective renal angiography were 77.3%, 71.4%, 48.1% and 4.9% respectively. Small (less than 3 cm), asymptomatic, simple lesions with adipose component may be observed annually by CT and US until more experiences is gained with surveillance of these patients. Embolization was useful for emergency cases or pre-treatment of nephron sparing surgery, but insufficient by itself. As there still remain problems in the diagnosis of RAML, especially in the case of very small tumors, in the case with almost no adipose component and in the case associated with renal cell carcinoma, the diagnosis of RAML should be made synthetically including angiography.