Renal angiomyolipoma: typical and atypical features

Renal angiomyolipoma is an uncommon lesion, well-known to the radiologists as one of the few lesions for which a specific diagnosis can be achieved on the basis of radiological findings. It contains variable amounts of adipose tissue, smooth muscle and vessels. It usually grows as single lesion, and it can be isolated or associated with tuberous sclerosis or with the more rare lymphangioleiomyomatosis. From a radiological point of view there are typical aspects that allow a confident diagnosis, whereas more rarely there are atypical aspects that make the diagnosis more controversial. In this review the clinical, macro and microscopic morphological aspects of angiomyolipoma are presented as well as the therapeutic approaches that can be adopted in different circumstances. The most frequent and the atypical characteristics that can be appreciated with diagnostic imaging are described as well.