Large Intratumoral Pseudoaneurysm in a Patient with Bleeding Renal Angiomyolipoma

Angiomyolipoma (AML) is the most common benign renal tumor. It is composed of an abnormal collection of 3 primary components: unusual abdominal blood vessels, clusters of adipocytes and sheets of smooth muscle. CT is the preferred imaging technique for diagnosing and characterizing AMLs. AMLs typically have a benign course, but patients occasionally present with complications, such as sudden pain or hypotension secondary to spontaneous hemorrhage in the tumor. If the patient is symptomatic, the tumor grows rapidly or is >4 cm, angiography and selective arterial embolization or renal-sparing surgical excisions of the tumor are the treatment of choice. Patients with AMLs treated with embolization generally have a favorable outcome.