Lipomas are the most common benign tumors. The can be found in any site where fat is normally present. An unusual variant is lipoma with a hemangiomatous component. Angiolipoma was established as a pathological entity in 1960. In 1974, pathologists established three microscopic characteristics for these type of tumors:
1) There must be gross evidence of tumor formation.
2) Mature lipoma cells must comprise at least 50% of the tumor.
3) There must be microscopically visible small blood vessel formation (i.e. angiomatous proliferation)
Angiolipomas are benign tumors that may come in one of two types: non-infiltrating & infiltrating.
Angiolipomas occur in 17% of all lipomas. Unlike regular lipomas, angiolipomas commonly cause pain and tenderness. They are usually located just below the skin; most commonly on the trunk and extremities. Angiolipoma of the breast is very rare and can masquerade as a lesion that is suspicious for carcinoma on a mammogram. Treatment for angiolipomas is simply excision.