Hemangiomas of infancy are benign (non-cancerous) vascular tumors composed of cells that normally line the blood vessels (endothelial cells).
They are the most common tumor of childhood, occurring in up to 10% of infants. Hemangiomas are seen in all racial groups but are more common in Caucasians. They also occur more frequently in girls and low-birth-weight (less than 1,000 grams) premature infants.
The cause of hemangiomas is not yet understood, but it is known that they are not related to drugs or medications that may have been taken during pregnancy, nor are they related to any known environmental exposures that may have occurred during that time. Rarely, in some families multiple family members over several generations have been affected, and this is related to a gene abnormality.
Hemangiomas of infancy almost always have a period of growth, which is referred to as their proliferative phase. This is followed by a period of shrinkage, referred to as their involutive phase. Most hemangiomas begin their proliferative (growth) phase shortly after birth. This phase usually lasts for 4 to 6 months, but can be longer or shorter. Each lesion has its own growth timetable. The involutive phase is much slower and can take as long as ten years. It is difficult to predict how long this shrinkage process will last. Lesions that involute slowly, over a long period of time, are much less likely to shrink completely. In some children, even those hemangiomas that do shrink completely may leave residual fatty tissue and telangiectasias (tiny dilated blood vessels) of the skin.
Rarely, hemangiomas are fully grown at birth and do not increase in size. These tumors are called congenital hemangiomas. Unlike hemangiomas of infancy, congenital hemangiomas either involute rapidly or not at all. Rapidly involuting congenital hemangiomas are referred to as RICH. Non-involuting congenital hemangiomas are referred to as NICH.
Hemangiomas of infancy may be visible at birth or may not be recognized until the first few weeks or even months of life. In general, however, most hemangiomas become evident by 2 to 3 weeks of age. Although they commonly occur on the head or neck (60%), they can occur in any region of the body. Some lesions are small and hardly visible, whereas others are large and readily observable. Most hemangiomas appear as single tumors, though 15% present with more than one lesion.
Hemangiomas are classified as superficial, deep, or combined, depending upon the involvement of the skin and other soft tissues.
As hemangiomas involute, they undergo a change in consistency and color, becoming softer and grayer. Eventually, the lesion is replaced internally by fatty tissue. The more visible involved skin is replaced by thin skin that appears more normal.
Although complications are uncommon, they can occur. Possible complications include ulcerations (skin breakdown), obstruction of vital functions such as vision, hearing, or breathing, and distortion of facial features.
Certain patterns of hemangioma presentation and certain locations are more problematic and more likely to cause complications. Children with these hemangiomas should be evaluated by a multidisciplinary team of pediatric specialists with special expertise in treating vascular anomalies.
Most hemangiomas involute completely and do not require treatment. Nevertheless, all children with significant hemangiomas should undergo a thorough evaluation and continued observation.
In a small percentage of patients in whom hemangiomas disappear completely, residual fatty tissue or superficial skin telangiectasias remain. To improve appearance, these patients may require surgery and/or laser therapy some time during childhood.
Treatment is dependent upon both the stage of growth (proliferation vs. involution) of the lesion, the presence of complications, and emotional needs and considerations. Observation, laser therapy, drug therapy, and surgical removal are the four most common management options. In some patients, a combination of several of these treatments may be used over a period of time.
Ulcerated hemangiomas may require aggressive wound care, treatment with topical antibiotics, laser therapy, and/or surgical removal.