Hemangiomas of infancy are benign (noncancerous) 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 percent 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.
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 percent), 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 percent present with more than one lesion.
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. Current research is focusing on the hemangioma precursor cell, which will help with our understanding of the origin of hemangiomas.
Each lesion has its own growth timetable. 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 four to six months, but can be longer or shorter. The involutive phase is much slower and can take as long as 10 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. Noninvoluting congenital hemangiomas are referred to as NICH.
Physical Description of Hemangiomas
We classify hemangiomas as superficial, deep, or combined, depending upon the involvement of the skin and other soft tissues. If the lesion is near the skin surface, it is referred to as a superficial hemangioma. Superficial lesions appear as bright red, raised or flat patches on the skin or a textured area that resembles the appearance of a strawberry. Veins radiating from the lesion also may be visible beneath the skin. If the hemangioma grows in the lower layers of the skin or in muscle, it is called a deep lesion. Deep hemangiomas have a gray to blue hue, but due to their depth they may not be noticed for many weeks or months after birth, although they are growing. This type of lesion is firmer and more rubbery to touch, and its color does not completely disappear when you press on the area. When a hemangioma has components of both superficial and deep lesions, we refer to it as a combined lesion. Combined lesions may have a layered combination of red on top and blue below. As hemangiomas shrink (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.
Diagnosis of Hemangiomas
In most cases, a diagnosis is made by correlating medical history with physical examination findings. If there is any uncertainty in distinguishing a hemangioma from other lesions or vascular malformations, ultrasonography (a noninvasive diagnostic tool) usually provides a definitive answer. In certain cases, magnetic resonance imaging (MRI) or computed tomography (CT), which are radiological tests, may also be necessary to make a diagnosis and determine the extent of the lesion. If there is any question regarding the possibility of a malignant (cancerous) growth, a biopsy will be performed. This involves removing a small section of tissue from the lesion for microscopic examination by a pathologist. Ultrasonography is performed with the child awake, while MRI and biopsy require general anesthesia. CT may be performed with or without under sedation depending on the age of the child.
Possible Complications with Hemangiomas
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.
Multiple skin hemangiomas often are associated with hemangiomas of internal organs, including the liver, lungs, and intestines. Rarely, even the brain is affected.Hemangiomas on the face that present in a distribution resembling a beard can be associated with airway involvement.
Some hemangiomas over the face and neck are associated with PHACE syndrome. This syndrome involves coexisting abnormalities of the posterior brain, the great vessels of the heart, the eye, and chest wall. Hemangiomas located over the lower back and spine can be associated with spinal defects. Hemangiomas involving the genital area can be associated with pelvic and urinary system abnormalities. Extensive liver hemangiomas can be associated with heart failure and hypothyroidism (low thyroid hormone).
Treatment and Management of Hemangiomas
Most hemangiomas shrink (involute) completely and do not require treatment. Nevertheless, all children with significant hemangiomas should undergo a thorough evaluation and continued observation. Decisions as to whether to treat and when to treat must be made on an individual basis, with consideration given not only to the physical functioning of the child, but also to prevention of permanent disfigurement and the emotional impact of the lesion.
In a small percentage of patients in whom hemangiomas disappear completely, residual fatty tissue or superficial skin telangiectasias (small widened blood vessels on the skin) remain. To improve appearance, these patients may require surgery and/or laser therapy some time during childhood. Even small facial hemangiomas can be treated now with topical agents.
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.
· Observation. In most cases, observation is the best course to follow, especially when the hemangioma is involuting and your child's functioning is not impaired.
· Laser therapy. Laser therapy is used to treat ulcerated hemangiomas and superficial residual skin telangiectasias.
· Drug therapy. Medical therapy is used for complicated hemangiomas in the proliferative phase. Their purpose is to slow the growth and decrease the size of the lesion and to prevent further complications. Medical therapy can be topical, injected, taken orally or given intravenously. Medications include:
· Propranolol – This medication is typically used orally. There is a topical applicant, but it is not the first line of drug choice.
· Timolol – This is a topical form of a drug similar to propranolol.
· Steroids – This medication can be applied topically for small lesions, injected in to the skin or taken orally. Not commonly used at the present time.
· Vincristine – This is used for complicated hemangiomas that do not respond to other treatments (used rarely).
· Surgery. Surgery may be advised for selected patients, including (1) children with painful and ulcerated hemangiomas that do not heal; (2) children whose lesions interfere with breathing, vision, or other vital functions; (3) those who have hemangiomas that do not completely involute; and (4) those in whom hemangiomas have resulted in unacceptable scarring or deformity.
Ulcerated hemangiomas may require aggressive wound care, treatment with topical antibiotics, laser therapy, and/or surgical removal.
Possible Risks With Treatment
While each of therapies mentioned above can be effective, each also involves certain risks or side effects.
· Laser therapy. During the early growth phase of hemangiomas, this has not proven to be effective and may result in some scarring and changes in skin pigmentation. These can often (but not always) be corrected by later cosmetic procedures.
· Drug therapy. Side effects disappear when the medication is stopped.
· Propranolol can cause a decrease in heart rate, blood pressure or blood sugar. These possible side effects are carefully monitored in the hospital setting, before the infant is discharged to home.
· Timolol very rarely causes side effects. However, some possibilities include decrease in heart rate, low blood pressure, weakness and fatigue, sleep disturbance and low blood sugar.
· Steroids can cause irritability, swelling of the face, stomach irritation and slowing of growth. Because of increased susceptibility to infection while on steroids, live virus vaccines should be avoided during steroid treatment.
· Vincristine can cause constipation, abnormalities in body salt levels, and neurologic symptoms.
· Surgery. Depending on the location and extent of the hemangioma, complications such as bleeding and infection may occur. Although surgical removal of a hemangioma results in significant improvement of appearance, there may be some scarring. When scarring is severe, it may be improved by subsequent scar revision surgery.