What Are Lymphatic Malformations?
A lymphatic malformation is a clump of abnormal lymph vessels that form a growing, disorganized, spongy cluster of cysts.
Lymphatic malformations appear as masses (unusual growths), but they are benign (not cancerous).
What Happens in Lymphatic Malformations?
The lymphatic (lim-FAT-ik) system is a network of tubes that collects lymph (LIMF) from body tissue and keeps body fluid levels balanced. This clear, pale yellow fluid drains out of blood vessels all over the body. The lymphatic system returns the lymph to the bloodstream. Lymphatic malformations grow because the lymph in their abnormal vessels can't drain out well and usually are separate from the normal vessel system. This makes them swell, which is known as a flare.
Lymphatic malformations also grow because they contain fragile malformed veins in their walls that bleed very easily. The lymphatic malformation can fill with blood. The pooling lymph or blood stretches the vessels and cysts, making the lymphatic malformation grow larger. If it's close to the skin surface, it can look bruised.
As a lymphatic malformation grows, it may put pressure on nearby body parts, such as the eyes, trachea (windpipe), or blood vessels. Lymphatic malformations may form inside skin, fat, connective tissue , joints, organs, or bones. They can form anywhere in the body but the brain, and are most common in the head and neck area.
There are two main types of lymphatic malformations:
- microcystic lymphatic malformations are spongy and have small vessels and tiny cysts.
- macrocystic lymphatic malformations (also called cystic hygromas or lymphangiomas) have large, stretched vessels and cysts filled with lymph, blood from internal bleeding, or both.
What Are the Signs & Symptoms of Lymphatic Malformations?
A lymphatic malformation usually appears as a growing, spongy-feeling lump. A child can have more than one lymphatic malformation, but they are usually in the same area of the body.
The skin over lymphatic malformations often has small bubbles, called vesicles (VESS-ih-kuls). These look like tiny blisters. The fluid in them starts out clear and colorless, but will turn dark red if blood leaks into it, as in other types of lymphatic malformations. These skin bumps can cause bleeding from the skin surface. Less commonly, the vesicles are filled with milky fluid called chyle (KYE-ul).
A child with a lymphatic malformation may have:
- overgrowth and swelling in affected areas (lips, tongue, jaws, cheeks, arms, legs, fingers, or toes)
- pain and swelling of the lymphatic malformation
- a tendency to injure the lymphatic malformation, causing bleeding, which can happen with very mild trauma or even with no known trauma
Some symptoms are related to the area of the body affected:
Tongue, windpipe, and mouth lymphatic malformations may cause problems with:
Orbit (eye socket) lymphatic malformations may cause:
- double vision
- bulging of the eye
Chest lymphatic malformations may cause:
- chest pain or pressure
- trouble breathing
- narrowing of the airways to the lungs
Lymphatic malformations in the gastrointestinal tract (gut) or pelvis can cause:
- bleeding from the rectum
- constipation (trouble pooping and pain)
- bladder obstruction (trouble peeing and pain)
- protein loss due to poor absorption and loss of lymph into the gut
Lymphatic malformations of the genitourinary tract (kidney and bladder) can cause:
- pain when peeing
Lymphatic malformations in bones can cause:
- bone overgrowth
- bone loss
- rarely, a fracture
What Causes Lymphatic Malformations?
Lymphatic malformations form very early in pregnancy, but doctors don't know why. Most lymphatic malformations are thought to happen at random during the baby's development. They're not caused by anything a woman did or didn't do during her pregnancy.
Some of the more severe lymphatic malformations do have genetic mutations identified. But they're also thought to happen randomly and are not inherited.
Lymphatic malformations are more common in children with:
- Down syndrome
- Turner syndrome
- an overgrowth syndrome (genetic disorders that cause an unusual increase in the size of the body or a body part)
- Noonan syndrome
How Are Lymphatic Malformations Diagnosed?
Lymphatic malformations may be seen on a prenatal (before birth) ultrasound scan. A lymphatic malformation not found earlier might be found when the baby is born.
Most significant lymphatic malformations are seen by age 2, after lymph fluid has built up and stretched the vessels of the lymphatic malformation or there is bleeding into it. But some aren't found until the teen years or later.
To be sure the lump is a lymphatic malformation and not another kind of tumor , doctors will do an exam and order imaging tests such as:
- ultrasound scan
- computed tomography (CT or CAT) scan
- MRI scan
How Are Lymphatic Malformations Treated?
Pediatric specialists often work together as a team to treat a child's lymphatic malformation.
The doctors involved may include:
- vascular and interventional radiologists
- genetic specialists
- orthopedic surgeons
- pediatric medical specialists (pulmonology, cardiology, etc.)
- pediatric surgeons
- ophthalmologists (eye surgeons)
- otolaryngologists (ear, nose, and throat surgeons)
- speech pathologists
The team will study the lymphatic malformation's type and location and consider the child's age, health, and other medical problems. They'll decide on a treatment that has the fewest side effects and risks, and offers the best results.
Things to know about treatment options:
- Most lymphatic malformations that appear suddenly will decrease in size and pain without treatment, but very rarely go away on their own.
- Incision (cutting into) and draining the lymph from a lymphatic malformation can temporarily reduce its size. This is usually only done for diagnosis or to treat an infection.
- Sclerotherapy (injection of a medicine into the lymphatic malformation) makes the lymph vessels collapse and scar together, shrinking the lymphatic malformation.
- Surgical removal is sometimes the best choice when the lymphatic malformation affects organs or interferes with speech, swallowing, or appearance. Minimally invasive surgery may be used, so the surgical scars are very small.
- Laser therapy may be used for lymphatic malformations in the skin or mouth.
- Radiofrequency ablation is sometimes used to treat lymphatic malformations in the tongue. A needle inserted into the lymphatic malformation sends out radio waves that ablate (destroy) the malformation.
- Medicines are often used for large lymphatic malformations. These are low-risk, generally well-tolerated, and shrink most lymphatic malformations over time.
Antibiotic treatment and drainage of the lymphatic malformation may be needed if it gets infected, which is rare.
What Else Should I Know?
Lymphatic malformations can grow back, so kids might need to have more than one treatment.
Kids may feel shy or embarrassed about how a lymphatic malformation looks. Be sure to support your child emotionally. It can help to find a local support group where other families can talk about what works for them. Ask your child's care team for recommendations. You also can look online at:
Talking to a therapist can help kids and teens if they're feeling sad or upset about a lymphatic malformation or its treatment.