Retroperitoneal bleeding from renal angiomyolipoma
CT revealed a large retroperitoneal hematoma and evidence of a new area of increased density. This density was consistent with hemorrhage and was noted primarily along the superior and anterior aspect of a previously seen heterogeneous fat-containing mass, which was consistent with AML (Figure 1).
For further evaluation, she was taken to the interventional radiology suite for arteriography (Figure 2). Aortography revealed tortuosity and small aneurysms arising from the left renal artery with diffuse small vessel irregularity, which is consistent with AML (Figure 2). Selective upper-pole arteriography showed an enlarged arterial feeder and slow extravasation (Figure 3).
In an effort to preserve the left kidney, embolization was performed using 1.5 vials of 350 to 500 micron polyvinyl alcohol (PVA) particles. The patient received a single transfusion immediately following the procedure to restore her baseline hemoglobin level. The patient's hemoglobin level remained stable throughout the remainder of the hospital stay.
Tuberous sclerosis is a genetic disease affecting 1 in 6000 newborns in the United States. It is a multisystem disease commonly presenting with seizures, mental retardation, behavioral problems, and skin abnormalities. Tumors can grow on any organ, but they most commonly occur on the brain, kidneys, heart, lungs, and skin.
Angiomyolipomas are benign growths consisting of fatty tissue and muscle cells. They occur in 40% to 80% of individuals with TS and usually occur between the ages of 20 and 30. In most cases, they usually do not produce symptoms; however, they can sometimes grow so large that they cause pain or kidney failure. Angio-myolipomas associated with TS are more often multiple, are larger, and bleed more often than sporadic AMLs.1 Bleeding can cause pain and weakness and, if severe, may not stop, which may result in anemia and a life-threatening drop in blood pressure, which warrants urgent medical attention. Eighty-two percent of AMLs that are >4 cm become symptomatic. The most common presenting symptoms include flank pain, palpable mass, and hematuria. Of symptomatic cases, >51% present with hemorrhage.2
Symptomatic tumors >4 cm should be considered for treatment by transcatheter arterial embolization (TAE), enucleation, or partial nephrectomy.2 As the sole therapy, TAE is effective in >90% of tumors and is the first choice of intervention for symptomatic AML.3 Asymptomatic tumors <4 cm should be monitored frequently.1,2
Angiomyolipomas may arise spontaneously or in the setting of tuberous sclerosis. Although generally benign, AMLs may become symptomatic, especially when associated with TS, and may present with pain or bleeding. Treatment options for bleeding AMLs include surgery and embolization. Embolization is the favored approach in most cases,as it may allow maximal preservation of renal function. Prophylactic embolization is also recommended to reduce the angiogenic component of renal AML and minimize risk of bleeding in large AMLs (>4 cm).