[Selective embolization of an aneurysm in a massive angiomyolipoma of the kidney]

Forty to 80% of patients with tuberous sclerosis exhibit renal angiomyolipomas which are often multiple and bilateral. Renal ultrasonography has a low sensitivity and a low specificity in the diagnosis of renal angiomyolipomas. Some patients have so many angiomyolipomas that ultrasonography indicates a confluence of angiomyolipomatous tissue throughout the kidney, in which case the size of a separate angiomyolipoma is difficult to estimate and the actual size may be underestimated. However it is an important tool in the follow-up of smaller lesions. With CT and magnetic resonance imaging, the diagnosis of these angiomyolipomas can always be confirmed due to the characteristic fat component. In addition, a better visualisation of the extension of the lesions can be obtained. Once the diagnosis of angiomyolipoma has been established a sonographic follow-up every 6 months is mandatory and feasible. Renal angiomyolipomas larger than 3.5 cm in diameter have a substantial risk for severe hemorrhage which should be treated by selective embolization.