[Renal angiomyolipoma: benign tumor?].

Often incidentally discovered, angiomyolipoma (AML) may be revealed by sudden flank pain secondary to perirenal hemorrhage. Tumoral vessels have an increased fragility, leading to potentially major blood loss. Diagnosis is based on the demonstration of a mass which is hyperechogenic by ultrasound and of partially negative density by CT scan. Our cases from 1979 to 1991 are reviewed. Clinical data, investigation and treatment are discussed. Although benign, this tumor may be associated with high morbidity.