Angiolipomas (also sometimes known as haemangiolipomas, vascular lipomas, and fibromyolipomas) are rare soft tissue tumors composed of mature adipocytes and vessels. They can occur essentially anywhere and can be subclassified into infiltrating and non-infiltrating variants 1.
Please refer to the epidural (spinal) angiolipoma article for a specific discussion. The remainder of this article describes the general features of peripheral angiolipomas.
Typically occur in young adults, appearing on the forearm (most common location), trunk and upper arm. They are more common in males. The most common presentation is of multiple, small (<2 cm), subcutaneous, tender nodules 2,3.
Infiltrating angiolipomas are much rarer than the non-infiltrating variant. They occur in children and adults and have no sex predilection. They most commonly appear in the muscles of the lower extremity, neck, and shoulder, and are usually painless 5.
As expected, these masses contain adipose tissue with prominent vascular supply.
Infiltrating angiolipoma is nonencapsulated and can contain phleboliths, heterotopic bone, and calcium salts. There are authors who conclude that it should be classified as an "intramuscular hemangioma" 2,4.
Appear as well-circumscribed, homogeneous hyperechoic masses 5,6.
Angiolipomas demonstrate signal intensity characteristics of mature adipose tissue. Vascular elements are T1-hypointense and T2 hyperintense and enhance vividly following administration of contrast 3.
Catheter angiography demonstrates prominent coarse neovascularity. During the capillary phase, contrast staining is typically seen 1.
Treatment and prognosis
Treatment is predominantly surgical, although infiltrating tumors are difficult to completely excise 1 and, as mentioned above, tend to recur locally. 2
- 1. Finberg HJ, Levin DC. Angiolipoma: a rare benign soft tissue tumor with a malignant arteriographic appearance. AJR Am J Roentgenol. 1977;128 (4): 697-8. doi:10.2214/ajr.128.4.697 - Pubmed citation
- 2. Kransdorf MJ, Moser RP, Meis JM, Meyer CA. Fat-containing soft-tissue masses of the extremities. Radiographics : a review publication of the Radiological Society of North America, Inc. 11 (1): 81-106. doi:10.1148/radiographics.11.1.1996399 - Pubmed
- 3. Gupta P, Potti TA, Wuertzer SD, Lenchik L, Pacholke DA. Spectrum of Fat-containing Soft-Tissue Masses at MR Imaging: The Common, the Uncommon, the Characteristic, and the Sometimes Confusing. Radiographics : a review publication of the Radiological Society of North America, Inc. 36 (3): 753-66. doi:10.1148/rg.2016150133 - Pubmed
- 4. Pribyl C, Burke SW, Roberts JM, Mackenzie F, Johnston CE. Infiltrating angiolipoma or intramuscular hemangioma? A report of five cases. Journal of pediatric orthopedics. 6 (2): 172-6. Pubmed
- 5. Mintz AD, Mengoni P. Angiolipoma of the breast: sonographic appearance of two cases. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 17 (1): 67-9. Pubmed
- 6. Lee JY, Kim SM, Fessell DP, Jacobson JA. Sonography of benign palpable masses of the elbow. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 30 (8): 1113-9. Pubmed