Year : 2010 | Volume
: 53 | Issue : 2 | Page : 340--341
Multifocal renal angiomyolipoma presenting as massive intraabdominal hemorrhage
Rashmi Kushwaha1, Indrani Dhawan1, Rashmi Arora1, Kusum Gupta1, JS Dhupia2,
1 Department of Histopathology, Safdarjung Hospital, New Delhi, India
2 Department of Pathology, Safdarjung Hospital, New Delhi, India
13 Vikram Vihar Extension, Lajpat Nagar IV, New Delhi
Angiomyolipomata of the kidney are unusual lesions composed of abnormal thick walled blood vessels, smooth muscle and adipose elements. These are asymptomatic and occasionally present with flank pain, a palpable mass or gross hematuria. They may be associated with tuberous sclerosis. The risk of bleeding is increased with size, and lesions greater than 4 cm have more than 50% chance of significant bleeding. An unusual case of multifocal renal angiomyolipoma associated with tuberous sclerosis and presenting as massive intra abdominal hemorrhage is reported.
|How to cite this article:|
Kushwaha R, Dhawan I, Arora R, Gupta K, Dhupia J S. Multifocal renal angiomyolipoma presenting as massive intraabdominal hemorrhage.Indian J Pathol Microbiol 2010;53:340-341
|How to cite this URL:|
Kushwaha R, Dhawan I, Arora R, Gupta K, Dhupia J S. Multifocal renal angiomyolipoma presenting as massive intraabdominal hemorrhage. Indian J Pathol Microbiol [serial online] 2010 [cited 2020 Jul 15 ];53:340-341
Available from: http://www.ijpmonline.org/text.asp?2010/53/2/340/64330
Renal angiomyolipoma have an incidence of 0.3-3% and arise from the mesenchymal elements of the kidney.  They are mostly benign tumors composed of varying proportions of mature adipose tissue, smooth muscle and abnormal thick walled blood vessels. ,
Angiomyolipomata have been described in the literature either as hamartomas or choriostomas. As fat and smooth muscle are not normal constituents of the renal parenchyma, angiomyolipoma by definition should be considered as choriostoma.
Spontaneous rupture of the kidney is rare but is a well-recognized surgical emergency. Resulting hematoma is confined to either the subcapsular or perinephric space. 
We describe a male patient of multifocal renal angiomyolipoma with massive intraabdominal hemorrhage resulting probably due to rupture of pseudo aneurysm of renal artery branch.
A 35 year old man presented in casualty with acute abdominal pain associated with nausea and hematuria. He had adenoma sebaceum on face. On radiological investigations renomegaly and a hyperechoic lesion at mid-pole of right kidney was seen, left kidney appeared normal. There was perinephric collection compressing the inferior vena cava. Contrast enhanced computed tomography of abdomen revealed multiple right sided renal angiomyolipoma with Perinephric and Subcapsular hematoma secondary to rupture of one of these masses and pseudo aneurysm in mid-polar segmental renal artery. During surgery large right-sided renal mass was found measuring 15 x 15 x 10 cm, abutting first and second part of duodenum, right gonadal vessels, ascending colon, hepatic flexure, liver and right side of diaphragm. Four hundred millilitre of blood was present in peritoneum.
Grossly, renal shape was distorted. Capsule was thickened. On cut section multiple tumors were identified, the largest measuring 6 x 5 cm. The tumor mass extended to perirenal fat. It was yellow to tan grey in appearance with areas of hemorrhage and necrosis. The compressed renal parenchyma was seen in between tumor masses [Figure 1].
Microscopically, appearance was similar in all the tumors consisting of tortuous, thick walled blood vessels and bundles of smooth muscle that seemed to emanate from vessel walls. Mature adipose tissue was present focally. Areas of hemorrhage and necrosis were seen. No nuclear atypia was identified. The diagnosis of angiomyolipoma was made [Figure 2] and [Figure 3]
Angiomyolipomata may occur as an isolated phenomenon or as part of the syndrome associated with tuberous sclerosis. The overall female to male predominance is approximately 4 : 1 to 8 : 1, suggesting role of female hormones to tumor growth.  Isolated angiomyolipoma occur sporadically, account for 80% of cases and are usually solitary that occur in the fourth to fifth decade of life (mean age 43 years).  Angiomyolipoma associated with tuberous sclerosis are typically larger than isolated angiomyolipoma, have multifocal or bilateral disease and tend to occur in younger patients.
This relatively young male patient had adenoma sebaceum and associated multiple renal angiomyolipoma, thus fulfilling two major criteria for tuberous sclerosis, so we did not recommend CT/MRI as presence of two major criterias is sufficient to diagnose tuberous sclerosis. This tumor was greater than 4 cm leading to rupture. In a study done by Steiner MS et al. it is described that multiple renal angiomyolipomas associated with tuberous sclerosis, occur at early age, are more symptomatic and grow rapidly. Although most angiomyolipoma are benign and asymptomatic, symptoms develop in 68-80% of patients when tumor size reaches 4 cm or more. Patients with ruptured angiomyolipoma often present with acute pain abdomen as a result of hemorrhage and up to 20% are in shock at the time of initial presentation. Therefore, it is important to predict the possibility of rupture in patients with angiomyolipoma.  In our patient, rupture of renal angiomyolipoma was associated with rupture of pseudoaneurysm of a renal artery branch.
Angiomyolipomas are composed of variable amounts of adipose tissue, smooth muscle and vasculature. Over 90% of the tumors contain at least focal areas of mature adipose tissue. The smooth muscle component ranges from fascicles of elongated spindle cells with cigar-shaped nuclei to sheets of epithelioid cells with abundant eosinophilic cytoplasm. Thickened and hyalinized vessels with eccentric lumens are seen in most cases. 
In conclusion, angiomyolipoma of kidney are unusual lesions that behave in benign fashion. Multifocal lesions associated with tuberous sclerosis grow at a rapid rate and are likely to undergo rupture if size exceeds 4 cm. The primary complication is intraabdominal hemorrhage. Hence this case report carries an important message to clinicians that tumor greater than 4 cm should be resected to avoid complications.
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