1147Vol. 10 | No. 4 | Autumn 2013 |U R O LO G Y J O U R N A L Multi-Detector Computed Tomography Angiography of a Ruptured Giant Renal Angiomyolipoma with Pseudoaneurysm and Associated Saccular Dilatation of Left Renal Artery Umesh C. Parashari, Sachin Khanduri, Samarjit Bhadury, Gaurav Singh Keywords: angiomyolipoma; tomography; X-ray computed; rupture; embolism; laparos- copy; magnetic resonance imaging. INTRODUCTION Angiomyolipoma (AML) is a neoplastic lesion consisting of mature blood vessels, smooth muscle cells and fat tissue. Its most common site is kidney. The common complication is rupture with intrarenal or peri lesional hemorrhage depending on size of the tumor. The treatment depends on the size and clinical features of the tumor, usually being embolization. CASE REPORT A 55-year old female presented with history of acute abdominal pain, localized to the left flank following a minor trauma after a fall. Lab investigations revealed low hemoglobin count and hematuria. On ultrasonography, a heterogenous mass measuring approximately 15 × 20 × 13 cm in the left renal area arising from the upper and mid pole region being vis- ible. A provisional diagnosis of renal mass with possible hemorrhage was made. On contrast enhanced computed tomography (CT) scan there was evidence of a large exophytic hetero- geneous mass measuring approximately 13.2 × 10.8 × 19.0 cm having predominantly fat attenuation (Figure 1). Mass lesion is in anterolateral cortex of upper and middle pole of left kidney displacing and compressing residual renal parenchyma posteromedially and lower pole anteromedially. CT angiography was done in the same setting. On angiography dilated tortuous left renal artery was seen with mild dilation of its branches supplying the mass le- sion. There was evidence of a large lobulated vascular sac like lesion of approximate size Corresponding author: Umesh Chandra Parashari, MD Department Radio Diagnosis, Era’s Lucknow Medical College, Lucknow, India Tel: +94 150 88926 E-mail: id-drumesh.rd@gmail.com Received June 2011 Accepted September 2011 Department Radio Diagnosis, Era’s Lucknow Medical College, Lucknow, India CASE REPORT 1148 | Case Report 7.4 × 4.8 × 7.0 cm in center of the lesion which showed homogenous filling in arterial phase and persistent filling in portal venous phase. Multiple small saccular dilatations of renal artery branches were also seen (Figure 2). A di- agnosis of large AML on left side with multiple saccular aneurysmal dilatations of branches of left renal artery was made. Patient was immediately taken for surgery and a par- tial nephrectomy was performed along with embolization of the pseudoaneurysm. The operated tumor tissue was sent for histopathology which confirmed our diagnosis of AML. DISCUSSION There are two types of AML: classic renal AML contain- ing smooth muscle, vascular, and fat tissue, and very rarely infiltrating perirenal tissue; and a second type of AML con- taining a large fourth component, perivascular epithelioid cells, making it more aggressive.(1,2,3) AML either occur in isolation or as multiple lesions associated with tuberous sclerosis in 20% of cases.(4) The AMLs are caused by mu- tations in either the tuberous sclerosis complex (TSC1) or TSC2 genes, which govern cell growth and proliferation.(5) The classic symptoms includes flank pain, a palpable ten- der mass or signs of internal bleeding caused by intracap- sular or retroperitoneal hemorrhage.(1,6) Few present with shock following hemorrhage due to rupture of blood ves- sels. Wünderlich's syndrome, a spontaneous retroperitoneal hemorrhage of non-traumatic origin occurs in up to 50% of patients with tumors less than 40 mm.(6) Abdominal CT Figure 1. Axial On contrast enhanced computed tomography (1A and 1B) and coronal reformation (1C) showing a large exophytic hetero- geneous left renal mass having predominantly fat attenuation (open white arrow) arising anterolateral cortex of upper and middle pole of left kidney with a thick rim of hyperdense hematoma (white arrow head). A large lobulated vascular sac like lesion is seen in the center of the mass (thick white arrow). Volume rendered coronal image (1D) during angiography phase showing dilated tortuous left renal artery (thin white arrow) with a large lobulated pseudoaneurysm in center of the mass (thick white arrow). 1149Vol. 10 | No. 4 | Autumn 2013 |U R O LO G Y J O U R N A L Giant Renal Angiomyolipoma | Parashari et al scanning is the diagnostic tool of choice to diagnose and differentiate between various causes of a renal mass, and assess the size of the AML and the extent of hemorrhage. (1,3) Fat density within a non-calcified renal mass remains the most important diagnostic finding of AML. On magnet- ic resonance imaging (MRI) sequences the tumor appears hyperintense on T1 weighted and T2 weighted sequences due to presence of fat. Recent advances in CT and MR angi- ography may improve the detection of aneurysm formation in these tumors.(7,8) Various treatment modalities available for AML depend upon its size. Embolization and partial or total nephrectomy are usually done. Larger lesions require treatment such as surgical excision or embolization. Me- dium sized lesions need monitoring and follow up.(9) Embo- lization is the preferred therapy and appears to be the most successful nephron sparing procedure or to reduce the size or to stop bleeding during acute situations. Life threatening complications can be avoided if diagnostic tests and thera- peutic interventions are readily available. CONFLICT OF INTEREST None declared. REFERENCES 1. Bissler JJ, Kingswood JC. Renal angiomyolipomata. Kidney Int. 2004;66:924-34. 2. Oesterling JE, Fishman EK, Goldman SM, Marshall FF. The management of renal angiomyolipoma. J Urol. 1986;135:1121-4. Figure 2. Computed tomography angiography MIP (maximum intensity projection) image shows dilated tortuous left renal artery (thin white arrow) and a large intra lesion pseudoaneurysm on left side (thick white arrow). 1150 | 3. Pruijm M T, Falke T H, Peltenburg H G. [Retroperitoneal bleeding caused by renal angiomyolipoma] Ned Tijdschr Geneeskd. 2003;147:1696-9. 4. Casper KA, Donelly LF, Chen B, Bissler JJ. Tuberous sclerosis complex: renal imaging findings. Radiology. 2002;225:451- 6. 5. Bissler JJ, Henske EP. Renal Manifestations of Tuberous Scle- rosis Complex. In: Tuberous Sclerosis Complex: From Genes to Therapeutics. In: Kwiatkowski DJ, Thiele EA, Whittemore V, editors. Weinheim, Germany: Wiley-Blackwell; 2010. p. 321-325. 6. Albi G, del Campo L, Tagarro D. Wunderlich's syndrome: causes, diagnosis and radiological management. Clin Ra- diol. 2002;57:840-5. 7. Joarder R, Gedroyc WM. Magnetic resonance angiography: the state of the art. Eur Radiol. 2001;11:446-453. 8. Hayashi H, Kawamata H, Ishio M, Kumazaki T. Multiple renal artery aneurysms diagnosed by three-dimensional CT angi- ography. Clin Imaging. 2000;24:221-23. 9. Dickinson M, Ruckle H, Beaghler M, Hadley HR. Renal an- giomyolipoma: optimal treatment based on size and symp- toms. Clin Nephrol. 1998;49:281-6. Case Report