Angiomyolipoma arising in the renal sinus: a difficult radiologic diagnosis.

We report a case of angiomyolipoma (AML) occurring in the renal sinus evaluated by intravenous urography (IVU), renal ultrasound (US), angiography, and computed tomography (CT). Imaging features of this lesion are identical to AMLs elsewhere, but preoperative diagnosis was complicated by the unusual occurrence of the tumor in this location in a patient with abdominal pain. Accurate preoperative diagnosis will allow tumorectomy or conservative management.