Hemangioma

A hemangioma is a congenital benign tumour or vascular malformation of endothelial cells (the cells that line blood vessels).

In infancy, it is the most common tumor.

Hemangioma
A small hemangioma of infancy

Terminology

Before considering the hemangioma it is important to understand that there have been recent changes in the terminology used to define vascular anomalies (abnormal lumps made up of blood vessels). The term hemangioma was originally used to describe any vascular tumour both present around birth or appearing later in life. Mulliken et al separated these conditions into a family of self-involuting tumours (growing lesions that eventually disappear) from the family of malformations (enlarged or abnormal vessels present at birth and essentially permanent). The importance of this separation is that it allows us to differentiate early in life 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). Unfortunately many textbooks and dictionaries are not up to date, creating great confusion.

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 look like a ripe strawberry, 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. They are formed either during gestation or most commonly they are not present at birth but appear during the first few weeks of life. They are often misdiagnosed, initially, as a scratch or bruise but the 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 races. Females are three to five times more likely to have hemangiomas than males. They 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. Although hemangiomas are benign, some serious complications can occur. Hemangiomas never develop as an adult but one misunderstanding is that all hemangiomas go away by the age of 10; very few do not. Many people say that they are a vascular malformation but they are, in fact, a hemangioma.

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, yet Duke researchers conducted genetic analyses of small nucleotide polymorphisms in hemangioma tissue compared to the mother's DNA that contradicted this notion. 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.

Types

• Capillary hemangioma - Also known as Strawberry Hemangiomas since they have a red strawberry-like look. They are benign and composed of capillaries, and appear early in life (usually the first few weeks). They enlarge during the first year of life (thus causing worry) but stop enlarging by the end of the first year and start involuting. Each year they involute more and more such that by the age of 9 years 90% of them have disappeared.

• Cavernous hemangioma - Appears in infancy and they persist. They are due deeper, more blood filled blood vessels and hence have a nodular purplish appearance but are completely benign. Biopsy is difficult, as blood is involved.

Complication

(Cavernous hemangioma on forehead)

The vast majority of hemangiomas are not associated with complications. Hemangiomas may break down on the surface to ulcers. 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 amblyopia. Very rarely, extremely large hemangiomas can cause high-output heart failure due to the amount of blood that must be pumped to excess blood vessels. Lesions adjacent to bone can also cause erosion of the bone.

The most frequent complaints about hemangiomas, however, stem from psychosocial complications: the condition can affect a person's appearance and can provoke attention and malicious reactions from others. Particular problems occur if the lip or nose is involved, as distortion can be difficult to treat surgically.

Children with large Segmental Hemangiomas of the head and neck can be associated with a disorder called PHACES Syndrome.

Treatment

Most hemangiomas disappear without treatment, leaving minimal or no visible marks. Large hemangiomas can leave visible skin changes secondary to severe stretching of the skin or damage to surface texture. When hemangiomas interfere with vision, breathing, or threaten significant cosmetic injury, they are usually treated.

The mainstay of treatment is oral corticosteroid therapy. Other drugs such as interferon or vincristine are sometimes considered if the corticosteroids do not work. If this fails, surgical removal often becomes necessary. Blockage of the airway will often require a tracheostomy to be performed (insertion of an external airway through the front of the neck into the trachea below the level of the obstruction). Smaller raised lesions are sometimes treated with injection of corticosteroid directly into the lesion. Pulsed dye laser can be useful for very early flat superficial lesions if they appear in cosmetically significant areas or for those lesions that leave residual surface blood vessels in the case of incomplete resolution. Unfortunately raised lesions or lesions under the skin do not respond to laser.

A beta-blocker called propranolol has helped a handful of patients with infantile hemangiomas.

Ulceration will usually heal with topical medication and special dressings under medical supervision. Sometimes pulsed dye laser can be used to accelerate healing.

There is also a rare effect of Hemangioma which can cause more serious complications.

Prognosis

Hemangiomas go through three stages of development and decay:

1. In the proliferation stage, a hemangioma grows very quickly. This stage can last up to twelve months.
2. In the rest stage, there is very little change in a hemangioma's appearance. This usually lasts until the infant is one to two years old.
3. In the involution phase, a hemangioma finally begins to diminish in size. Fifty percent of lesions will have disappeared by age five with the vast majority gone by puberty.

Historical Cases

One of the burials of the Arras Culture in prehistoric Britain, "Wetang Woman" displayed skeletal evidence of a considerable haemangioma on her face. The incredibly rich burial has been interpreted as a sign she was respected in her community, and not feared or reviled due to her facial haemangioma.