Reviewed by Brian R. Robinson, MD
Hemangiomas are abnormal growths of blood vessels that may occur in any vascularized tissue. They occur most frequently on the surface of the skin or just under the skin, but may also occur in internal organs, muscle, and bone. Hemangiomas on the face can be disfiguring and may interfere with visual development or cause airway obstruction.
There are several kinds of hemangiomas. Some (congenital hemangiomas) are present at birth, and others (infantile hemangiomas) develop within the first few months of life, and others still (including intramuscular hemangiomas, kaposiform hemangiomas) can develop in older patients. They occur when vascular structures grow abnormally, causing a knot of them to form. The proximity and density of the structures in a hemangioma causes the discoloration, because the tissue is turgid with the blood that travels through the malformed vascular structures.