Table of ContentsView AllTable of ContentsTypesSymptomsCausesDiagnosisTreatmentPrognosisCoping
Table of ContentsView All
View All
Table of Contents
Types
Symptoms
Causes
Diagnosis
Treatment
Prognosis
Coping
Anangiomyolipomais a type of tumor that usually occurs in yourkidneys. It is the most common benign (noncancerous) solid renal (kidney) tumor type.
In most cases, symptoms don’t appear until this type of tumor has grown and spread. The problem can lead to a severe type ofhemorrhage(bleeding) that can threaten your life without treatment.
This article describes angiomyolipoma symptoms, causes, diagnosis, treatment, and outlook for the problem.
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Types of Angiomyolipoma
Types of angiomyolipomas are commonly classified according to the makeup of the tumor. Most angiomyolipomas contain dilated blood vessels, smooth muscle cells, and mature adipocytes (certain fat cells.)
Generally, the classification of an angiomyolipoma considers these three components in identifying a tumor as one of the following types:
Typical (triphasic) angiomyolipomas: These tumors make up the majority of angiomyolipomas. They contain all three components in various proportions.
Atypical (monophasic or epithelioid) angiomyolipomas: These tumors are less common. They are further divided according to the following criteria:
What Is Kidney Disease?
Angiomyolipoma Symptoms
Though rare, symptoms typically occur when the tumor grows to 40 millimeters (mm) (a little over 1.5 inches) or larger and begins to spread. In tumors of this size, symptoms can occur in 80% of cases and can include the following:
A 40 mm or larger angiomyolipoma can cause spontaneous retroperitoneal hemorrhage, also called Wunderlich syndrome. This rare but potentially life-threatening condition involves bleeding in the area behind your abdominal cavity. It affects fewer than 15% of people who have these tumors.
What is a Nephrologist? When to See One and What to Expect
The specific causes of angiomyolipomas are unknown. About 80% of these tumors occur as isolated masses. These tumors have a higher prevalence in women. Most are found when people are in their late 40s or early 50s, though they can occur at any age.
The remaining 20% of angiomyolipomas typically occur in patients withtuberous sclerosis complex (TSC), a rare genetic disease that causes benign tumors in organ systems like the kidneys. Angiomyolipomas occur in up to 75% of patients with tuberous sclerosis complex. There usually is more than one tumor and they’re bilaterally located (found on both sides).
How Is Angiomyolipoma Diagnosed?
Most angiomyolipomas contain fat tissue that is visible in imaging studies. Since the detection of adipose tissue is considered the primary criterion for the diagnosis of classic angiomyolipomas, diagnosis is usually based on one of the following types of imaging:
While imaging studies are usually sufficient to diagnose an angiomyolipoma, the findings may be inconclusive in cases of low-fat or fat-invisible angiomyolipomas. For these tumors, apercutaneousrenalbiopsyis advised. This procedure uses a thin needle inserted through the skin to extract kidney tissue samples for analysis.
The findings from a percutaneous renal biopsy can distinguish a low-fat or fat-invisible tumor from papillaryrenal cell carcinoma, which may be easily confused with a fat-invisible angiomyolipoma.
Treatment Options for Angiomyolipoma
Treatment of angiomyolipomas is usually limited to a small number of patients who have this condition. Most tumors are small, benign, and exist without symptoms.
Watchful waiting, which involves observing the condition for signs of worsening, is usually advised for these cases. Annual or semiannual imaging studies may be used to track the risk of rupture.
The primary indications for treatment involve preventing the rupture of the tumor. Certain factors increase the risk of rupture. Treatment may be advised if you have an angiomyolipoma and any of the following risk factors for rupture:
When necessary, treatment involves one of the following:
Research indicates that up to 91% of angiomyolipomas are asymptomatic with slow growth, averaging a rate of 0.02 centimeters (cm) a year. However, angiomyolipomas with tuberous sclerosis complex tend to grow faster and have a higher transformation rate than malignant tumors.
The frequency of symptoms increases with the size of an angiomyolipoma. As these tumors grow to 40 mm and larger, treatment is usually advised to counter the risk of tumor rupture. The spontaneous rupture of angiomyolipomas is the most common cause of retroperitoneal bleeding, which can become life-threatening.
Small, slow-growing angiomyolipomas typically don’t cause symptoms, so you may not know the problem exists until it is discovered during an imaging study for another reason. If you are diagnosed with this type of tumor, you may be advised to continue to follow up with your healthcare provider so your tumor can be monitored for changes that could increase the risk of rupture.
An angiomyolipoma that causes symptoms or increases in size may require treatment, though it may be difficult to determine the source of your pain without imaging studies. Consult a healthcare provider if you notice any changes in the appearance and sensation of your abdominal area. This can help you identify problems with undiagnosed or diagnosed angiomyolipoma as early as possible.
Summary
An angiomyolipoma is one of the most common benign kidney tumors. It usually occurs without symptoms. It is often found during a CT scan or MRI for another health problem.
The most common type is small and grows slowly. Treatment is usually unnecessary, though the tumor may be observed for growth and changes.
There are no known causes for this type of tumor. A rare genetic disease called tuberous sclerosis complex raises your risk of having it. Tumors, in these cases, are more likely to grow faster and become cancerous.
Larger tumors have a higher risk of rupture in the abdominal cavity. Treatment is used to reduce this risk or to treat bleeding when it occurs. Without treatment, bleeding can have severe outcomes.
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Park BK.Renal angiomyolipoma: radiologic classification and imaging features according to the amount of fat.American Journal of Roentgenology. 2017;209(4):826-835. doi:10.2214/AJR.17.17973Vos N, Oyen R.Renal angiomyolipoma: the good, the bad, and the ugly.J Belg Soc Radiol. 102(1):41. doi:10.5334/jbsr.1536Flum, AS, Hamoui, N, Said, MA, et al.Update on the diagnosis and management of renal angiomyolipoma.J Urol. 2017; 195(4): 834–846. doi:10.1016/j.juro.2015.07.126Fejes Z, Sánta F, Jenei A, Király IE, Varga L, Kuthi L.Angiomyolipoma of the kidney—clinicopathological analysis of 52 cases.Pathol Oncol Res. 2023;0. doi:10.3389/pore.2022.1610831Wang C, Li X, Peng L, Gou X, Fan J.An update on recent developments in rupture of renal angiomyolipoma.Medicine. 2018;97(16):e0497. doi:10.1097/MD.0000000000010497Coombs EJ.Role of mTOR inhibition in the treatment of patients with renal angiomyolipomas.J Am Assoc Nurse Pract. 2013;25(11):588-596. doi:10.1002/2327-6924.12081Lim A, Abel EJ.Contemporary management of renal angiomyolipomas.Translational Cancer Research. 2016;5(Suppl 6). doi:10.21037/tcr.2016.11.57Seyam RM, Alkhudair WK, Kattan SA, Alotaibi MF, Alzahrani HM, Altaweel WM.The risks of renal angiomyolipoma: reviewing the evidence.J Kidney Cancer VHL. 2017;4(4):13-25. doi:10.15586/jkcvhl.2017.97
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Park BK.Renal angiomyolipoma: radiologic classification and imaging features according to the amount of fat.American Journal of Roentgenology. 2017;209(4):826-835. doi:10.2214/AJR.17.17973Vos N, Oyen R.Renal angiomyolipoma: the good, the bad, and the ugly.J Belg Soc Radiol. 102(1):41. doi:10.5334/jbsr.1536Flum, AS, Hamoui, N, Said, MA, et al.Update on the diagnosis and management of renal angiomyolipoma.J Urol. 2017; 195(4): 834–846. doi:10.1016/j.juro.2015.07.126Fejes Z, Sánta F, Jenei A, Király IE, Varga L, Kuthi L.Angiomyolipoma of the kidney—clinicopathological analysis of 52 cases.Pathol Oncol Res. 2023;0. doi:10.3389/pore.2022.1610831Wang C, Li X, Peng L, Gou X, Fan J.An update on recent developments in rupture of renal angiomyolipoma.Medicine. 2018;97(16):e0497. doi:10.1097/MD.0000000000010497Coombs EJ.Role of mTOR inhibition in the treatment of patients with renal angiomyolipomas.J Am Assoc Nurse Pract. 2013;25(11):588-596. doi:10.1002/2327-6924.12081Lim A, Abel EJ.Contemporary management of renal angiomyolipomas.Translational Cancer Research. 2016;5(Suppl 6). doi:10.21037/tcr.2016.11.57Seyam RM, Alkhudair WK, Kattan SA, Alotaibi MF, Alzahrani HM, Altaweel WM.The risks of renal angiomyolipoma: reviewing the evidence.J Kidney Cancer VHL. 2017;4(4):13-25. doi:10.15586/jkcvhl.2017.97
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Park BK.Renal angiomyolipoma: radiologic classification and imaging features according to the amount of fat.American Journal of Roentgenology. 2017;209(4):826-835. doi:10.2214/AJR.17.17973Vos N, Oyen R.Renal angiomyolipoma: the good, the bad, and the ugly.J Belg Soc Radiol. 102(1):41. doi:10.5334/jbsr.1536Flum, AS, Hamoui, N, Said, MA, et al.Update on the diagnosis and management of renal angiomyolipoma.J Urol. 2017; 195(4): 834–846. doi:10.1016/j.juro.2015.07.126Fejes Z, Sánta F, Jenei A, Király IE, Varga L, Kuthi L.Angiomyolipoma of the kidney—clinicopathological analysis of 52 cases.Pathol Oncol Res. 2023;0. doi:10.3389/pore.2022.1610831Wang C, Li X, Peng L, Gou X, Fan J.An update on recent developments in rupture of renal angiomyolipoma.Medicine. 2018;97(16):e0497. doi:10.1097/MD.0000000000010497Coombs EJ.Role of mTOR inhibition in the treatment of patients with renal angiomyolipomas.J Am Assoc Nurse Pract. 2013;25(11):588-596. doi:10.1002/2327-6924.12081Lim A, Abel EJ.Contemporary management of renal angiomyolipomas.Translational Cancer Research. 2016;5(Suppl 6). doi:10.21037/tcr.2016.11.57Seyam RM, Alkhudair WK, Kattan SA, Alotaibi MF, Alzahrani HM, Altaweel WM.The risks of renal angiomyolipoma: reviewing the evidence.J Kidney Cancer VHL. 2017;4(4):13-25. doi:10.15586/jkcvhl.2017.97
Park BK.Renal angiomyolipoma: radiologic classification and imaging features according to the amount of fat.American Journal of Roentgenology. 2017;209(4):826-835. doi:10.2214/AJR.17.17973
Vos N, Oyen R.Renal angiomyolipoma: the good, the bad, and the ugly.J Belg Soc Radiol. 102(1):41. doi:10.5334/jbsr.1536
Flum, AS, Hamoui, N, Said, MA, et al.Update on the diagnosis and management of renal angiomyolipoma.J Urol. 2017; 195(4): 834–846. doi:10.1016/j.juro.2015.07.126
Fejes Z, Sánta F, Jenei A, Király IE, Varga L, Kuthi L.Angiomyolipoma of the kidney—clinicopathological analysis of 52 cases.Pathol Oncol Res. 2023;0. doi:10.3389/pore.2022.1610831
Wang C, Li X, Peng L, Gou X, Fan J.An update on recent developments in rupture of renal angiomyolipoma.Medicine. 2018;97(16):e0497. doi:10.1097/MD.0000000000010497
Coombs EJ.Role of mTOR inhibition in the treatment of patients with renal angiomyolipomas.J Am Assoc Nurse Pract. 2013;25(11):588-596. doi:10.1002/2327-6924.12081
Lim A, Abel EJ.Contemporary management of renal angiomyolipomas.Translational Cancer Research. 2016;5(Suppl 6). doi:10.21037/tcr.2016.11.57
Seyam RM, Alkhudair WK, Kattan SA, Alotaibi MF, Alzahrani HM, Altaweel WM.The risks of renal angiomyolipoma: reviewing the evidence.J Kidney Cancer VHL. 2017;4(4):13-25. doi:10.15586/jkcvhl.2017.97
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