Angiomyolipoma

Small bowel (small intestine)
Benign tumors and tumor-like conditions
Angiomyolipoma

Topic Completed: 1 May 2010

Revised: 22 August 2019

Copyright: 2003-2019, PathologyOutlines.com, Inc.

PubMed Search: Angiomyolipoma small bowel

See also: Kidney tumor chapter

Page views in 2018: 594

Page views in 2019 to date: 534

Table of Contents

Cite this page: Pernick N. Angiomyolipoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/smallbowelangiomyolipoma.html. Accessed October 16th, 2019.

Definition / general

Benign triphasic tumor composed of dysmorphic, thick walled blood vessels, smooth muscle that appears to spin off from vessel walls and mature lipid distended cells

Etiology

Member of PEComa family, a concept first proposed by Bonetti (Am J Surg Pathol 1992;16:307), which comprises mesenchymal tumors with perivascular clear cells and epithelioid features that coexpress melanocytic and muscle markers
Occasionally associated with tuberous sclerosis (OMIM: Tuberous Sclerosis 1 [Accessed 16 February 2018])

Clinical features

Usually arises in the kidney (eMedicine: Kidney Angiomyolipoma Imaging [Accessed 16 February 2018]) or occasionally in the liver (Arch Pathol Lab Med 2008;132:1679)
Gastrointestinal angiomyolipoma is very rare

Case reports

First documented case of symptomatic ileal angiomyolipoma was in a 60 year old woman suffering from intermittent periumbilical pain (Korean J Gastroenterol 2000;36:250)
Second case of ileal angiomyolipoma occurred in a 48 year old woman with vague abdominal pain and bloody stool (J Gastroenterol 2005;40:200)
28 year old man with with ileal intussusception (World J Gastroenterol 2009;15:1398)

Prognosis and treatment

Typically benign behavior at other sites but occasionally is invasive with metastases (Am J Surg Pathol 1991;15:1083)

Gross images

Images hosted on other servers:

Various images

Microscopic (histologic) description

Benign triphasic tumor composed of dysmorphic, thick walled blood vessels, smooth muscle that appears to spin off from vessel walls and mature lipid distended cells
Tumors occasionally have bizarre epithelioid smooth muscle cells (Int J Surg Pathol 2000;8:67) and possible multinucleation

Microscopic (histologic) images

Images hosted on other servers:

Various images

Positive stains

HMB45 and MelanA / A103, SMA, calponin, CD117, S100 (Am J Surg Pathol 2002;26:493)

Negative stains

Keratin

Differential diagnosis

Theoretically broad, encompassing smooth muscle and lipogenic tumors but narrowed when one carefully identifies the components of the tumor; few other tumors are immunoreactive for both smooth muscle and melanocytic markers
Leiomyomas and leiomyosarcomas have a prominent smooth muscle component but lack a prominent vascular or adipose component
Melanomas have prominent atypia, necrosis and infiltrative borders