Renal Hamartoma (Angiomyolipoma)

Renal hamartomas are considered benign tumors, probably arising from congenital rests within the organ. They contain various amounts of fat and smooth-muscle elements and are often rich in blood vessels. As a result of their “mixed” character, they have been variously designated as lipomata or angiolipomata (13), fibrolipomata, angiofibrolipoma, etc. (4, 8, 10, 11, 15, 16). While they have been frequently seen in patients with tuberous sclerosis (2, 5, 6, 12), most patients with this tumor do not suffer from tuberous sclerosis. Five cases studied by arteriography have been reported in the literature: in 4 translumbar aortography (8, 11, 17, 18) was employed, and in 1 the Seldinger approach and aortic flush (9). The angiographic pattern has been highly reminiscent of a malignant tumor. We had an opportunity to confirm this appearance in the case reported below. In addition, by utilizing a selective approach and intraarterial injection of epinephrine, we demonstrated a “neoplastic response” of the vessels involved in this lesion, i.e., a lack of vasoconstriction. Case Report A 50-year-old white male was admitted to a hospital in Atlanta, Ga., on Feb. 15, 1966, following an episode of severe, sudden, abdominal pain associated with shock and massive hematuria. He responded to several units of blood, and following stabilization various studies were carried out. A left renal mass was found, and surgery advised. The patient refused operation and returned to Miami, where he was admitted to the South Miami Hospital on April 30. At this time he was asymptomatic. Physical findings were essentially noncontrib-utory. No masses in the abdomen were palpated. The patient was afebrile, mildly hypertensive. There were no physical signs of tuberous sclerosis. Laboratory studies included urinary analysis, venereal disease tests, and investigation of blood urea nitrogen, the sedimentation rate, prothrombin time, bleeding and coagulation times, etc. All results were within normal limits. Nephrotomography demonstrated a lesion 5 cm in diameter, with a lucid center but a thick wall, in the cortex of the midpole of the left kidney. Selective renal arteriography on May 5, with injection of 8 cc of 75 per cent Hypaque, showed the cortical lesion to consist of a central avascular zone surrounded by a rim of pathological-appearing vessels. There were puddling of the contrast material and tumor stain, as well as an avascularity within the central portion, suggesting either necrosis or hemorrhage within the tumor. Subsequently, 0.25 μg of epinephrine was injected into the renal artery and followed in twenty-five seconds by an injection of 8 cc of 75 per cent Hypaque. A generalized constriction of the vessels supplying the normal renal parenchyma was noted, but an uninhibited visualization of the previously observed abnormal vascularity occurred.