Angiomyolipoma pathophysiology: Difference between revisions
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There is a special variant called an epithelioid angiomyolipoma, composed of more plump, epithelial looking cells, often with nuclear atypia, that have a described risk of malignant behaviour. | There is a special variant called an epithelioid angiomyolipoma, composed of more plump, epithelial looking cells, often with nuclear atypia, that have a described risk of malignant behaviour. | ||
===Microscopic Pathology=== | ===Microscopic Pathology=== | ||
Microscopic features of angiomyolipoma: | |||
*Smooth muscle | *Smooth muscle | ||
*Adipose tissue - not always present<ref name=pmid15584043>{{Cite journal | last1 = Crapanzano | first1 = JP. | title = Fine-needle aspiration of renal angiomyolipoma: cytological findings and diagnostic pitfalls in a series of five cases. | journal = Diagn Cytopathol | volume = 32 | issue = 1 | pages = 53-7 | month = Jan | year = 2005 | doi = 10.1002/dc.20179 | PMID = 15584043 }}</ref> - '''key feature''' | *Adipose tissue - not always present<ref name=pmid15584043>{{Cite journal | last1 = Crapanzano | first1 = JP. | title = Fine-needle aspiration of renal angiomyolipoma: cytological findings and diagnostic pitfalls in a series of five cases. | journal = Diagn Cytopathol | volume = 32 | issue = 1 | pages = 53-7 | month = Jan | year = 2005 | doi = 10.1002/dc.20179 | PMID = 15584043 }}</ref> - '''key feature''' | ||
*Abundant [[blood vessel]]s | *Abundant [[blood vessel]]s | ||
[[Image:Renal angiomyolipoma (1).jpg|200px|1. Histopathologic image of renal angiomyolipoma. Nephrectomy specimen. H & E stain.]] | [[Image:Renal angiomyolipoma (1).jpg|200px|1. Histopathologic image of renal angiomyolipoma. Nephrectomy specimen. H & E stain.]] | ||
[[Image:Renal angiomyolipoma (2).jpg|200px|2. Histopathologic image of renal angiomyolipoma. Nephrectomy specimen. The same case as demonstrated in "Image 1". H & E stain.]] | [[Image:Renal angiomyolipoma (2).jpg|200px|2. Histopathologic image of renal angiomyolipoma. Nephrectomy specimen. The same case as demonstrated in "Image 1". H & E stain.]] | ||
Revision as of 17:17, 29 September 2015
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Angiomyolipoma Microchapters |
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Angiomyolipoma pathophysiology On the Web |
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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.
Pathophysiology
Three components of an angiomyolipoma include:
- Vascular cells
- Immature smooth muscle cells
- Fat cells
They are 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 three components:
- blood vessels (-angio)
- plump spindle cells (-myo)
- adipose tissue (-lipoma)
Genetics
Angiomyolipoma is caused by a defect in the TSC1 and TSC2 gene.
Associated Conditions
Diseases associated with angiomyolipoma include:
Pathology
Gross Pathology
On gross pathology, well circumscribed and uniform yellow mass are characteristic findings of angiomyolipoma.
Variants
- Epithelioid angiomyolipoma
There is a special variant called an epithelioid angiomyolipoma, composed of more plump, epithelial looking cells, often with nuclear atypia, that have a described risk of malignant behaviour.
Microscopic Pathology
Microscopic features of angiomyolipoma:
- Smooth muscle
- Adipose tissue - not always present[2] - key feature
- Abundant blood vessels
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Cytologic
Cytologic features of angiomyolipoma include:[2]
- Nuclei - round/ovoid.
- Chromatin - bland.
Immunohistochemistry
Immunohistochemistry markers of angiomyolipoma include:
- Melanocytic markers positive[3]
- HMB-45 positive in all cases (15/15)[4]
- Melan A positive in ~87% of cases (13/15)
- Epithelial markers negative[3]
- EMA
- AE1/AE3
- SMA positive
- CD117 positive/negative
- Ki-67:[5]
- 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 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.