Page 9 - Journal of Laser Dentistry 1

Hemangioma

The terminology used to define, describe and categorize vascular anomalies, abnormal lumps made up of blood vessels, has changed. The term hemangioma was originally used to describe any vascular tumor-like structure, whether it was present at or around birth or appeared later in life. Mulliken et al. categorized these conditions into two families: a family of self-involuting tumors, growing lesions that eventually disappear, and another family of malformations, enlarged or abnormal vessels present at birth and essentially permanent. The importance of this distinction is that it makes it possible for early-in-life differentiation between lesions that will resolve versus those that are permanent. Examples of permanent malformations include port-wine stains (capillary vascular malformation) and masses of abnormal swollen veins (venous malformations).

Presentation

Hemangiomas are connected to the circulatory system and filled with blood. The appearance depends on location. If they are on the surface of the skin, they are reminiscent of a ripe strawberry (hence, they are sometimes referred to as "strawberry hemangiomas"); however, if they are just under the skin they present as a bluish swelling. Sometimes they grow in internal organs such as the liver or larynx. In most cases, hemangiomas will disappear over time. Some are formed during gestation; the most common are not congenital, but appear during the first few weeks of life. They are often initially misdiagnosed as a scratch or bruise; but the correct diagnosis becomes obvious with further growth. Typically, at the earliest phase in a superficial lesion, one will see a bluish red area with obvious blood vessels and surrounding pallor. Sometimes they present as

a flat red or pink area. Hemangiomas are the most common childhood tumor, occurring in approximately ten percent of Caucasians, and are less prevalent in other ethnicities. Females are three to five times as likely to have hemangiomas as males. Hemangiomas are also more common in twin pregnancies. Approximately 80% are located on the face and neck, with the next most prevalent location being the liver.

Causes

The cause of hemangioma is currently unknown; however, several studies have suggested the importance of estrogen signaling in hemangioma proliferation. In 2007, a paper from the Stanford Children's Surgical Laboratory revealed that localized soft tissue hypoxia coupled with increased circulating estrogen after birth may be the stimulus. There is also a hypothesis presented by researchers at Harvard and the University of Arkansas that maternal placenta embolizes to the fetal dermis during gestation resulting in hemangiomagenesis,. However, researchers at Duke University conducted genetic analyses of small nucleotide polymorphisms in hemangioma tissue compared to the mother's DNA that contradicted this hypothesis. More research is required in order to fully understand the explosive nature of hemangioma growth, which will hopefully yield targeted therapeutics to treat its most complicated presentations.

Complications

The vast majority of hemangiomas are not associated with complications. Hemangiomas may break down on the surface, called ulceration. If the ulceration is deep, significant bleeding may occur in rare occasions. Ulceration on the diaper area can be painful and problematic. If a hemangioma develops in the larynx, breathing can be compromised. A hemangioma can grow and block one of the eyes, causing an occlusion