Lymphatic malformations (LMs) are masses that result from an abnormal formation of small tube-like vessels that collect and transfer fluid in the body's tissue and are part of the immune system. In the normal lymphatic system, extra fluid is collected from the tissues and transported through a series of these vessels back into the body’s veins. With a lymphatic malformation, however, transfer of this fluid through these vessels is slowed down. The extra fluid builds up and dilates the vessels, which causes the affected area to swell, and sometimes, soft tissues and bones to enlarge. Older names for these malformations are lymphangiomas or cystic hygromas.

LMs are most commonly seen in the neck, face and armpit, but they can involve any area of the body. If they occur in the mouth or tongue, they can cause problems with eating and breathing. The masses steadily increase in size, although some enlarge more rapidly than others. Conditions such as infections or trauma can cause them to get larger suddenly (though this may be temporary).

What Causes Lymphatic Malformations?

Although the exact cause of lymphatic malformations is unknown, it is believed that they form in the early stages of pregnancy. There is no evidence that the condition is related to any known drug or medication that may have been taken during pregnancy or to any environmental exposure that may have occurred during that time. There is also no evidence that LMs are genetic.

What Are the Symptoms of Lymphatic Malformations?

When LMs occur in the skin, they look like tiny clear bubbles that often become dark red due to bleeding. In the neck and the armpit, LMs typically lie just beneath the skin and appear as a swelling of the area.

The masses can also occur in other organs and in bones and may cause more extensive enlargement in those areas as well. They can cause the enlargement of any part of the body, including the lip, cheek, ear, tongue, limb, finger or toe.

Concerns

Sometimes an infection in nearby tissues or in the lesion itself can occur and cause pain, significant swelling and cosmetic problems. It may lead to a serious infection. Bacteria may readily enter through open areas of the skin and may quickly spread. When this occurs, your child should take antibiotics. Bleeding into the LM also causes pain and swelling.

LMs often get bigger when the child has a viral or bacterial infection anywhere in the body. Therefore preventing infections and treating them quickly is very important.

Additional complications may occur, depending upon the specific area of the body that is affected by the lesion:

If it involves the trachea (windpipe), tongue or chest, it can cause difficulty breathing.
If it involves the gastrointestinal tract (stomach and intestines), it can cause protein loss.
If it involves the thorax (chest), it can cause a leakage of lymphatic fluid into the chest cavity. It can also cause heart and lung complications.
If it involves the abdomen, it can cause a leakage of lymphatic fluid into the abdomen.
If it involves a bone, it can cause bony destruction and pain.

Although certain complications cannot be prevented, they can sometimes be reduced. For example, careful attention to good oral hygiene may reduce the likelihood of your child developing an infection in an LM of the head and neck region. Teeth should be brushed regularly and thoroughly, and they should be cleaned by a dental hygienist more often than usual.

How Are Lymphatic Malformations Diagnosed?

Usually, your child’s medical history and physical examination will be enough for your doctor to make the diagnosis. Sometimes, however, an LM can be confused with or mixed with a venous malformation. Magnetic resonance imaging (MRI) and computed tomography (CT) are sometimes used to confirm the diagnosis.

Before birth, LMs can often be detected by an ultrasound.

How Are Lymphatic Malformations Treated?

Surgical removal — Surgery is a good treatment for some LMs, especially those that are found in one specific area. Also, surgical removal may be used as part of an overall treatment plan that includes one or more treatment approaches. Unfortunately, when the masses are extensive and surround many vital structures, surgery may not be possible. Risks include scarring and possible damage to structures involved with the lesion.

Sclerotherapy (direct injection of an irritating agent) — For large smooth clear masses under normal or bluish, sclerotherapy brings good results in about 80% of cases. This treatment, however, has limited effect on lesions that are made of many tiny spaces. Risks include scarring, and the LM may possibly come back.

Laser therapy — Surgical lasers are used sometimes, depending on the complexity of the lesion, along with other approaches. Laser therapy requires multiple treatments that are spaced out over several months. Risks include scarring and/or changes in skin pigmentation.

Radio frequency ablation — This relatively new technique uses high-energy radio frequency sound waves to selectively destroy some skin LMs. As with other treatment approaches, it may be used along with other treatment options. Risks: Minor bleeding and infection.

Chemotherapeutic agents — Widespread, life-threatening lymphatic malformations that cannot be removed with surgery are sometimes treated with chemotherapy and other medical treatments.

Types

The following are specific types of lymphatic malformations:

Gorham syndrome (Gorham-Stout syndrome) — A type that occurs in bones and partially destroys them.
Milroy disease — An inherited generalized swelling that typically occurs in the legs that is present at birth.
Lymphangioma circumscriptum — A skin type that has persistent, multiple groups of translucent “bumps” that usually contain clear lymph fluid.
Angiokeratoma — A group of skin lesions that are raised, dark red to black in color, and about 1mm to 10 mm in size. They often bleed very easily.