Intra-sinusal renal angiomyolipoma. Differential diagnosis from renal artery aneurysm

We report a case of atypical renal angiomyolipoma (AML) because of its clinic presentation like colic renal pain, its uncommon intrasinusal location, its low fatty content, and especially because of the diagnostic doubt with a renal artery aneurysm that could not be resolved before the surgery in spite of making Doppler ultrasound, renal one sided arteriography, computed tomography (CT) and magnetic resonance imaging (MRI). We gave up doing a percutaneous needle biopsy because of the location, the association with hematoma and the possibility of a vascular origin. It has been said that diagnostic images, mainly ultrasound and CT, have a high capacity to get a renal AML diagnosis before the surgery. However when there is an atypical characteristics association like we have talked about, dismissing other pathologies is necessary. We believe AML must be considered one of these because of its difficult differential diagnosis.