Traumatic rupture of renal angiomyolipoma managed with angioembolization followed by elective surgery: a report of two cases.

Abstract

Renal angiomyolipoma (AML) is a rare benign neoplasm of kidney origin. It is mainly comprised of varying amounts of adipose tissue, smooth muscle, and blood vessels. Most patients with small tumors have no clinical symptoms and the tumors are frequently detected by ultrasound or computed tomography (CT). The tumor size is always related to clinical symptoms. Steiner et al. reported that patients with tumor sizes greater than 4 cm were more frequently symptomatic (46%) and required surgery (54%). Spontaneous rupture of renal AML is the most severe complication. Koh and George speculated that large intratumoral pseudoaneurysm on contrast-enhanced CT was an important predictor or potential life-threatening tumor hemorrhaging. Yamakado et al. demonstrated that groups with spontaneous tumor ruptures have significantly larger sizes of tumors and aneurysm than groups with unruptured ones. Tumor size of 4 cm or larger and aneurysm size of 5 mm or larger were used as predictors of rupture. In the acute setting of a hemorrhage, transarterial embolization has been used as the treatment of choice for hemostasis in cases of stable hemodynamics. This could provide immediate access to locate the precise site of bleeding and to block the bleeder at the same time. On the other hand, angioembolization may occlude the aneurysm, destroy solid mass, and eventually, may reduce the size of parts of the tumors. When the patient’s clinical condition was stable after embolization, elective surgery or CT follow-up was recommended. Regarding the traumatic rupture of renal AML, there have been no reports related to its management. Here, we report two cases of renal AML with traumatic rupture, and suggest the management guidelines for this kind of tumor rupture. CASE REPORTS Case 1 A 31-year-old female was struck by a car while she was riding a motorcycle. Two weeks before the accident, she had palpated a mass on her right abdomen and was scheduled to receive radiologic investigation in a hospital. She was initially sent to a local hospital. No specific examinations or treatments were performed there, and she was discharged 6 hours after admission. The next morning she complained of severe pain over her right abdomen and flank. She was immediately brought to our emergency department (ED). On arrival, initial homodynamic status was stable, but physical examination revealed a huge tender mass palpated on the right side of her abdomen and flank. Gross hematuria was also noted. Abdominal CT showed a huge mass, which measured 10 15 cm and contained adipose tissue, was ruptured with perirenal hematoma and contrast extravasation on the right kidney (Fig. 1). Hypovolemic shock (blood pressure was 73/28 mm Hg) developed 4 hours after her arrival. Resuscitation, crystalloid (1,000 cc) and blood transfusion (red blood cells, 2 units) made her hemodynamics return to normal. Renal angiography was performed immediately. It revealed a space-occupying lesion from the low pole of the right kidney and abnormal hyper tropic arteries with multiple tiny aneurysms (1–2 mm) and contrast extravasation (Fig. 2). Transcatheter arterial embolization with micro-coil and gel form powder was performed. Two days after the accident, respiratory distress developed and end tracheal intubation was performed; diffusion haziness of the right lung field was found on chest x-ray film. A chest tube was inserted on the right and 800 cc of blood initially flowed out. Right flank pain was complained of and persistent drop of hemoglobin was noted. Due to suggested ongoing tumor hemorrhaging, repeated angiography (Figure 3) was performed and it demonstrated a small pseudoaneurysm (2 mm) with contrast extravasation of the inferior branch of right renal artery. Microcoil embolization was performed. Her condition became stable after two of arterial embolizations. Due to huge and fragile ruptured tumor with indistinct anatomy, elective nephrectomy including the mass was performed 1 month after admission. The pathology demonSubmitted for publication May 16, 2003. Accepted for publication January 20, 2004. Copyright © 2005 by Lippincott Williams & Wilkins, Inc. From the Department of Trauma and Emergency Surgery, Surgical Department, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Address for reprints: Yu-Pao Hsu MD, Department of Trauma and Emergency Surgery, Chang Gung Memorial Hospital, Chang Gung University, 5 Fushing Street, Taoyuan, Taiwan; email: yupao@cgmh.org.tw.