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A Review of the Literature on Extrarenal Retroperitoneal Angiomyolipoma
1North Manchester General Hospital Department of Urology, Delaunay's Road, Manchester, UK.
Background:
Extrarenal retroperitoneal angiomyolipomas are rare.
Aim:
To review the literature.
Results:
Angiomyolipomas, previously classified as hamartomas, are now classified as benign tumours. Thirty cases of primary retroperitoneal angiomyolipomas have been reported. Diagnosis of the disease upon is based radiological and pathological findings of triphasic features of (a) fat and (b) blood vessels and myoid tissue. Immunohistochemistry tends to be positive for HMB45, MART1, HHF35, calponin, NKI-C3, and CD117. The lesion is common in women. Treatment options have included the following: (a) radical surgical excision of the lesion with renal sparing surgery or radical nephrectomy in cases where malignant tumours could not be excluded and (b) selective embolization of the lesion alone or prior to surgical excision. One case of retroperitoneal angiomyolipoma was reported in a patient 15 years after undergoing radical nephrectomy for angiomyolipoma of kidney and two cases of distant metastases of angiomyolipoma have been reported following radical resection of the tumour.
Conclusions:
With the report of two cases of metastases ensuing surgical resection of the primary lesions there is need for academic pathologists to debate and review angiomyolipomas to decide whether to reclassify angiomyolipomas as slow-growing malignant tumours or whether the reported cases of metastases were de novo tumours or metastatic lesions.
Insights
Extrarenal retroperitoneal angiomyolipomas are rare benign tumors, predominantly affecting women. Diagnosis relies on imaging and pathology. Recent cases suggest potential metastasis, prompting reclassification debate.
Area of Science:
- Oncology
- Pathology
- Radiology
Background:
- Extrarenal retroperitoneal angiomyolipomas are exceptionally rare tumors.
- Previously considered hamartomas, they are now classified as benign neoplasms.
Purpose of the Study:
- To conduct a comprehensive literature review on retroperitoneal angiomyolipomas.
- To analyze diagnostic criteria, treatment modalities, and recent findings regarding metastatic potential.
Main Methods:
- Literature review of reported cases of retroperitoneal angiomyolipomas.
- Analysis of diagnostic features including radiological, pathological, and immunohistochemical findings.
- Review of treatment outcomes and reported cases of metastasis.
Main Results:
- Thirty cases of primary retroperitoneal angiomyolipomas have been documented.
- Diagnosis is characterized by triphasic features: fat, blood vessels, and myoid tissue.
- Immunohistochemistry typically shows positivity for HMB45, MART1, HHF35, calponin, NKI-C3, and CD117.
- Common in women, treatment includes surgical excision or embolization.
- Two cases of metastasis following resection and one late recurrence after nephrectomy raise concerns.
Conclusions:
- The occurrence of metastases necessitates a re-evaluation of angiomyolipomas.
- Debate is needed on whether to reclassify them as slow-growing malignant tumors or consider alternative explanations for metastases.
- Further research is required to clarify the behavior and classification of these rare tumors.
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