Angiomyolipoma overview: Difference between revisions
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==Historical Perspective== | ==Historical Perspective== | ||
Angiomyolipoma was first described as a tumor in 1911 by Fisher.He also noted and described its association with the Tuberous Sclerosis.It has been named as Angiomyolipoma by Morgan and associates in 1951. | |||
==Classification== | ==Classification== | ||
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==Differentiating Angiomyolipoma from other Diseases== | ==Differentiating Angiomyolipoma from other Diseases== | ||
Angiomyolipoma must be differentiated from [[retroperitoneal liposarcoma]], [[adrenal myelolipoma]], and [[renal cell carcinoma]].<ref name=pmid25517956>{{Cite journal | last1 = Patil | first1 = PA. | last2 = McKenney | first2 = JK. | last3 = Trpkov | first3 = K. | last4 = Hes | first4 = O. | last5 = Montironi | first5 = R. | last6 = Scarpelli | first6 = M. | last7 = Nesi | first7 = G. | last8 = Aron | first8 = M. | last9 = Sangoi | first9 = AR. | title = Renal Leiomyoma: A Contemporary Multi-institution Study of an Infrequent and Frequently Misclassified Neoplasm. | journal = Am J Surg Pathol | volume = | issue = | pages = | month = Dec | year = 2014 | doi = 10.1097/PAS.0000000000000354 | PMID = 25517956 }}</ref><ref name=aaa> Renal angiomyolipoma differential diagnosis. Dr Matt A. Morgan and Dr Behrang Amini et al. Radiopaedia 2015. http://radiopaedia.org/articles/renal-angiomyolipoma</ref> | Angiomyolipoma must be differentiated from [[retroperitoneal liposarcoma]], [[adrenal myelolipoma]], and [[renal cell carcinoma]].<ref name="pmid25517956">{{Cite journal | last1 = Patil | first1 = PA. | last2 = McKenney | first2 = JK. | last3 = Trpkov | first3 = K. | last4 = Hes | first4 = O. | last5 = Montironi | first5 = R. | last6 = Scarpelli | first6 = M. | last7 = Nesi | first7 = G. | last8 = Aron | first8 = M. | last9 = Sangoi | first9 = AR. | title = Renal Leiomyoma: A Contemporary Multi-institution Study of an Infrequent and Frequently Misclassified Neoplasm. | journal = Am J Surg Pathol | volume = | issue = | pages = | month = Dec | year = 2014 | doi = 10.1097/PAS.0000000000000354 | PMID = 25517956 }}</ref><ref name="aaa">Renal angiomyolipoma differential diagnosis. Dr Matt A. Morgan and Dr Behrang Amini et al. Radiopaedia 2015. http://radiopaedia.org/articles/renal-angiomyolipoma</ref> | ||
==Epidemiology and Demographics== | ==Epidemiology and Demographics== | ||
The [[incidence]] of angiomyolipoma is approximately 30 per 100,000 individuals worldwide. Females are more commonly affected with angiomyolipoma than males. Angiomyolipoma commonly affects individuals older than 40 years of age.<ref name=aaa>Raediopedia.org.http://radiopaedia.org/articles/renal-angiomyolipoma</ref> | The [[incidence]] of angiomyolipoma is approximately 30 per 100,000 individuals worldwide. Females are more commonly affected with angiomyolipoma than males. Angiomyolipoma commonly affects individuals older than 40 years of age.<ref name="aaa">Raediopedia.org.http://radiopaedia.org/articles/renal-angiomyolipoma</ref> | ||
==Risk Factors== | ==Risk Factors== | ||
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==Screening== | ==Screening== | ||
Patients who have [[tuberous sclerosis]] should be screened for angiomyolipoma. Abdominal [[CT scan]] is recommended for screening of angiomyolipoma.<ref name=aaa>Futrelle J. Five Millions by Wireless. Kessinger Publishing; 2004.</ref> | Patients who have [[tuberous sclerosis]] should be screened for angiomyolipoma. Abdominal [[CT scan]] is recommended for screening of angiomyolipoma.<ref name="aaa">Futrelle J. Five Millions by Wireless. Kessinger Publishing; 2004.</ref> | ||
==Natural History, Complications and Prognosis== | ==Natural History, Complications and Prognosis== | ||
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Cafer Zorkun, M.D., Ph.D. [2], Faizan Sheraz, M.D. [3]
Overview
Angiomyolipoma is a benign renal neoplasm previously considered to be a hamartoma or choristoma, but now known to be neoplastic.[1] It is composed of variable amounts of fat, vascular, and smooth muscle elements. The fat density of the tumor on CT has been regarded to be pathognomonic. The lesion is well demarcated and contains mature elements. It occurs in more than 50% of individuals with tuberous sclerosis, often bilaterally. On gross pathology, well circumscribed and uniform yellow mass is characteristic finding of angiomyolipoma. Angiomyolipoma is caused by a defect in the TSC1 gene. Angiomyolipoma must be differentiated from retroperitoneal liposarcoma, adrenal myelolipoma, and renal cell carcinoma. If left untreated, small angiomyolipomas and those without dilated blood vessels (aneurysms) cause few symptoms. Small angiomyolipomas are associated with the most favorable prognosis. Common complications of angiomyolipoma include infection, hematuria and hemorrhage. Abdominal CT scan may be diagnostic for angiomyolipoma. On CT scan, angiomyolipoma is characterized by smooth tumor margin with low intratumoral fat component and homogenous enhancement on both corticomedullary and excretory phase scans.[2] Surgery is not the first-line treatment option for patients with angiomyolipoma. Transcatheter arterial embolization is usually reserved for patients with complicated disease.[3]
Historical Perspective
Angiomyolipoma was first described as a tumor in 1911 by Fisher.He also noted and described its association with the Tuberous Sclerosis.It has been named as Angiomyolipoma by Morgan and associates in 1951.
Classification
Angionmyolipoma may be classified according to radiologic appearance into 7 subtypes: classic angiomyolipoma, triphasic angiomyolipoma, fat poor angiomyolipoma, hyperattenuating angiomyolipoma, isoattenuating angiomyolipoma, angiomyolipoma with epithelial cysts, and angiomyolipoma in lymphangioleiomyomatosis.[4]
Pathophysiology
On gross pathology, a well-circumscribed and uniform yellow mass is characteristic 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.
Causes
Angiomyolipoma is caused by a mutation in the TSC1 gene. It can also be caused by a defect in TSC2 gene.
Differentiating Angiomyolipoma from other Diseases
Angiomyolipoma must be differentiated from retroperitoneal liposarcoma, adrenal myelolipoma, and renal cell carcinoma.[5][6]
Epidemiology and Demographics
The incidence of angiomyolipoma is approximately 30 per 100,000 individuals worldwide. Females are more commonly affected with angiomyolipoma than males. Angiomyolipoma commonly affects individuals older than 40 years of age.[6]
Risk Factors
Tuberous sclerosis is a risk factor for the development of angiomyolipoma. Approximately 50% of individuals with tuberous sclerosis develop bilateral angiomyolipomas.
Screening
Patients who have tuberous sclerosis should be screened for angiomyolipoma. Abdominal CT scan is recommended for screening of angiomyolipoma.[6]
Natural History, Complications and Prognosis
If left untreated, small angiomyolipomas and those without dilated blood vessels (aneurysms) cause few symptoms. Small angiomyolipomas are associated with the most favorable prognosis. Common complications of angiomyolipoma include infection, hemorrhage, and shock.
History and Symptoms
Symptoms of angiomyolipoma include fever, nausea, vomiting, and abdominal pain.
Physical Examination
Common physical examination findings of angiomyolipoma include fever, flank tenderness, and palpable mass.
Laboratory Findings
Laboratory findings consistent with the diagnosis of angiomyolipoma include presence of red blood cells in urine and elevated white blood cell count.
CT
Abdominal CT scan may be diagnostic for angiomyolipoma. On CT scan, angiomyolipoma is characterized by smooth tumor margin with low intratumoral fat component and homogenous enhancement on both corticomedullary and excretory phase scans.[2]
MRI
Abdominal MRI may be diagnostic of angiomyolipoma. On MRI, angiomyolipoma is characterized by high signal intensity on non-fat saturated sequences and loss of signal following fat saturation.
Ultrasound
On abdominal ultrasound, angiomyolipoma is characterized by hyperechoic lesions and posterior acoustic shadowing in the cortex.
Other Imaging Studies
On digital subtraction angiography, angiolipoma is characterized by hypervascular lesions, microvascular aneurysms, and absent AV shunting.
Medical Therapy
There is no medical therapy for angiomyolipoma. The mainstay of therapy is embolisation.
Surgery
Surgery is not the first-line treatment option for patients with angiomyolipoma. Transcatheter arterial embolization is usually reserved for patients with complicated disease.[3]
References
- ↑ Eble JN. Angiomyolipoma of the kidney. Semin Diagn Pathol 1988;15:21-40
- ↑ 2.0 2.1 Kim JK, Park SY, Shon JH, Cho KS (2004). "Angiomyolipoma with minimal fat: differentiation from renal cell carcinoma at biphasic helical CT". Radiology. 230 (3): 677–84. doi:10.1148/radiol.2303030003. PMID 14990834.
- ↑ 3.0 3.1 Lewis JH, Weingold AB (1985). "The use of gastrointestinal drugs during pregnancy and lactation". Am J Gastroenterol. 80 (11): 912–23. PMID 2864852.
- ↑ Jinzaki M, Silverman SG, Akita H, Nagashima Y, Mikami S, Oya M (2014). "Renal angiomyolipoma: a radiological classification and update on recent developments in diagnosis and management". Abdom Imaging. 39 (3): 588–604. doi:10.1007/s00261-014-0083-3. PMC 4040184. PMID 24504542.
- ↑ Patil, PA.; McKenney, JK.; Trpkov, K.; Hes, O.; Montironi, R.; Scarpelli, M.; Nesi, G.; Aron, M.; Sangoi, AR. (2014). "Renal Leiomyoma: A Contemporary Multi-institution Study of an Infrequent and Frequently Misclassified Neoplasm". Am J Surg Pathol. doi:10.1097/PAS.0000000000000354. PMID 25517956. Unknown parameter
|month=ignored (help) - ↑ 6.0 6.1 6.2 Renal angiomyolipoma differential diagnosis. Dr Matt A. Morgan and Dr Behrang Amini et al. Radiopaedia 2015. http://radiopaedia.org/articles/renal-angiomyolipoma