Angiomyolipoma pathophysiology

	Angiomyolipoma Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Angiomyolipoma from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
Diagnostic Study of Choice
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
X-ray
CT
MRI
Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Angiomyolipoma pathophysiology On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Angiomyolipoma pathophysiology All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Angiomyolipoma pathophysiology
CDC on Angiomyolipoma pathophysiology
Angiomyolipoma pathophysiology in the news
Blogs on Angiomyolipoma pathophysiology
Directions to Hospitals Treating Angiomyolipoma
Risk calculators and risk factors for Angiomyolipoma pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2] Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [3], Faizan Sheraz, M.D. [4]

Overview

On gross pathology, well circumscribed and uniform yellow mass is characteristic finding of angiomyolipoma. The components of an angiomyolipoma include vascular cells, immature smooth muscle cells and fat cells. Angiomyolipoma is caused by a defect in TSC1 gene. Diseases associated with angiomyolipoma include von Hippel-Lindau syndrome and tuberous sclerosis. Cytologic features of angiomyolipoma include round nuclei and bland chromatin. Immunohistochemistry markers of angiomyolipoma include positive melanocytic markers.

Pathophysiology

Three components of an angiomyolipoma include:

Vascular cells
Immature smooth muscle cells
Fat cells

Angiomyolipoma is derived from a common progenitor cell that suffered the common second hit mutation. Angiomyolipomas are members of the perivascular epithelioid cells tumor group (PEComas) and are composed of variable amounts of these three components.

Genetics

Angiomyolipoma is caused by a defect in:

TSC1 gene

TSC2 gene

Associated Conditions

Diseases associated with angiomyolipoma include:

Gross Pathology

On gross pathology, well circumscribed and uniform yellow mass are characteristic findings of angiomyolipoma.

Microscopic Pathology

Microscopic features of angiomyolipoma:^[2]

Histopathologic slide of renal angiomyolipoma. Nephrectomy specimen. H & E stain.^[3]
Histopathologic slide of renal angiomyolipoma. Nephrectomy specimen. H & E stain.^[3]
Histopathologic slide of renal angiomyolipoma. Nephrectomy specimen. H & E stain.^[3]
Histopathologic image of renal angiomyolipoma. Nephrectomy specimen. HMB-45 immunostain.^[3]

Variants

Epithelioid angiomyolipoma
- There is a special variant called an epithelioid angiomyolipoma, composed of epithelial looking cells, often with nuclear atypia

Cytologic

Cytologic features of angiomyolipoma include:^[2]

Nuclei - round/ovoid
Chromatin - bland

Immunohistochemistry

Immunohistochemistry markers of angiomyolipoma include:

Melanocytic markers positive^[4]
- HMB-45 positive in all cases (15/15)^[5]
- Melan A positive in ~87% of cases (13/15)
Epithelial markers negative^[4]
- EMA
- AE1/AE3
SMA positive
CD117 positive/negative
Ki-67:^[6]
- Epithelioid variant of angiomyolipoma positive
- Conventional angiomyolipoma negative

References

↑ Image courtesy of Dr Andrew Ryan. Radiopaedia (original file [1]).[http://radiopaedia.org/licence Creative Commons BY-SA-NC
↑ ^2.0 ^2.1 Crapanzano, JP. (2005). "Fine-needle aspiration of renal angiomyolipoma: cytological findings and diagnostic pitfalls in a series of five cases". Diagn Cytopathol. 32 (1): 53–7. doi:10.1002/dc.20179. PMID 15584043. Unknown parameter |month= ignored (help)
↑ ^3.0 ^3.1 ^3.2 ^3.3 http://librepathology.org/wiki/index.php/Angiomyolipoma
↑ ^4.0 ^4.1 Template:Ref GUP
↑ Esheba, Gel S.; Esheba, Nel S. (2013). "Angiomyolipoma of the kidney: clinicopathological and immunohistochemical study". J Egypt Natl Canc Inst. 25 (3): 125–34. doi:10.1016/j.jnci.2013.05.002. PMID 23932749. Unknown parameter |month= ignored (help)
↑ Ooi, SM.; Vivian, JB.; Cohen, RJ. (2009). "The use of the Ki-67 marker in the pathological diagnosis of the epithelioid variant of renal angiomyolipoma". Int Urol Nephrol. 41 (3): 559–65. doi:10.1007/s11255-008-9473-1. PMID 18839327.

Template:WikiDoc Sources

[1] Image courtesy of Dr Andrew Ryan. Radiopaedia (original file [1]).[http://radiopaedia.org/licence Creative Commons BY-SA-NC

[pmid15584043-2] 2.0 ^2.1 Crapanzano, JP. (2005). "Fine-needle aspiration of renal angiomyolipoma: cytological findings and diagnostic pitfalls in a series of five cases". Diagn Cytopathol. 32 (1): 53–7. doi:10.1002/dc.20179. PMID 15584043. Unknown parameter |month= ignored (help)

[aaa-3] 3.0 ^3.1 ^3.2 ^3.3 http://librepathology.org/wiki/index.php/Angiomyolipoma

[Ref_GUP324-4] 4.0 ^4.1 Template:Ref GUP

[pmid23932749-5] Esheba, Gel S.; Esheba, Nel S. (2013). "Angiomyolipoma of the kidney: clinicopathological and immunohistochemical study". J Egypt Natl Canc Inst. 25 (3): 125–34. doi:10.1016/j.jnci.2013.05.002. PMID 23932749. Unknown parameter |month= ignored (help)

[pmid18839327-6] Ooi, SM.; Vivian, JB.; Cohen, RJ. (2009). "The use of the Ki-67 marker in the pathological diagnosis of the epithelioid variant of renal angiomyolipoma". Int Urol Nephrol. 41 (3): 559–65. doi:10.1007/s11255-008-9473-1. PMID 18839327.

[1]

[2]

[3]

[4]

[5]

[6]