Lymphatic Malformations

What is a lymphatic malformation (LM)?

lymphatic malformationLymphatic malformations (LM) are sponge-like collections of abnormal tubes (lymphatic vessels) that carry lymph fluid around the body.

Normally, the lymphatic system keeps fluids in balance and helps fight infections, along with the immune system. It collects extra fluid from the tissues and carries it through a series of small vessels back into the bloodstream.

With an LM, the flow of lymph fluid slows or stops. Fluid builds up in the body's tissues and lymphatic vessels. When the buildup is close to the skin, you can see a lump. LMs come in all sizes and can happen anywhere on the body. Most are on the head or neck.

  • Related conditions

    An LM can occur alone or as part of other conditions:

    • Lymphangiomatosis: LMs that are widespread in bone and soft tissue
    • Gorham-Stout disease: LMs that erode the underlying bone
    • Overgrowth: LMs with overgrowth of the adjacent bone and soft tissues
    • CLOVES syndrome
    • Noonan syndrome
    • Turner syndrome
    • Klippel-Trenaunay syndrome (KTS)
  • What causes an LM?

    LMs develop before birth but may not be noticed until later. LMs happen because of genetic changes (called mutations or variants). Most often, the affected gene is PI3KCA.

    The abnormal gene is not passed down by parents (not inherited). The mutation starts in 1 cell. Any cells that divide from that cell will continue the mutation. This is called a mosaic mutation.

Lymphatic Malformations at Seattle Children's

Our Vascular Anomalies Program is nationally known for treating children with LMs and other vascular disorders. We are 1 of the largest and most experienced programs in the United States.

Doctors from across the United States send children here for treatment because of our specialized expertise. We see nearly 2,000 children with vascular anomalies each year, more than any other hospital in the region.

For more information, contact the Vascular Anomalies Program by email or by calling 206-987-4606.

If you would like an appointment, ask your child’s primary care provider to refer you.

Providers, see how to refer a patient

  • The experts you need are here
    • We have treated hundreds of children with LMs. Doctors with less experience might confuse an LM for a different type of vascular anomaly, leading to the wrong treatment.
    • Our Vascular Anomalies team brings together experts with many different skills and experiences. These include otolaryngologists, dermatologists, plastic surgeons, general surgeons, ophthalmologists, geneticists and interventional radiologists.
    • Our physician-scientists help set national standards for care of young people with vascular anomalies. We provide the most advanced treatments in our region.
  • Accurate diagnosis and precision medicine
    • A correct diagnosis is the first step toward improving your child's condition. We have the expertise to accurately diagnose your child’s LM. If tests are needed to confirm it, we have a broad range of options, such as genetic testing and imaging studies. We will work with you to decide the best treatment option for your child.
    • Our physician-scientists have created a gene panel to test patients’ tissue and body fluids for the genetic changes known to cause vascular anomalies. We can test DNA in tissue sent to us from doctors across the nation. No other children’s hospital has a gene panel certified for clinical use with vascular malformations. This certification means doctors can make treatment decisions based on the results.
    • The gene panel helps us identify the exact genetic cause of an LM in some children. A precise diagnosis may expand your child’s treatment options to include drugs that target the overactive biological pathway causing the malformation. These targeted therapies may be newly developed or already approved for other diseases.
    • Our genetic testing expertise helps us create new therapies that we offer in research studies called clinical trials.
    • Learn more about vascular anomalies research at Seattle Children’s.
  • Making treatment easier on your child
    • Until Seattle Children’s pioneered glue embolization surgery (GES), many children with vascular malformations endured repeated, painful injections or multiple surgeries. To make it safer and easier to remove an LM in a single surgery, our team first injects medical-grade Super Glue.
    • For children who need surgery to remove an LM in the face, we use facial nerve mapping. This greatly reduces the risk of nerve injury and scarring.
  • Team approach for complete care
    • We schedule visits so your child sees all the specialists they need in as few days as possible. In some cases, we can consult via video phone calls with doctors or patients.
    • Your child’s team will work together — and with you — to make a treatment plan that fits your child’s unique needs. Combining our skills helps make sure your child gets the very best care.
    • As long as needed, our team keeps a watch on your child’s condition. We are always here to answer your questions and connect you to community resources.
  • We treat your whole child
    • Our specialty is treating children’s disease while helping them grow up to be healthy and productive. 
    • Children do not react to illness, injury, pain and medicine in the same way as adults. They need – and deserve – care designed just for them. Our experts focus on how treatments today affect growing bodies in the future. We plan your child’s treatment based on years of experience plus the newest research on what works best – and most safely – for children.
    • At Seattle Children's, we work with many children and families from around the Northwest and beyond. Whether you live nearby or far away, we can help with financial counseling, schooling, housing, transportation, interpreter services and spiritual care. Read about our services for patients and families.

Symptoms of an LM

LMs may be:

  • Just under the skin (superficial) or deep inside the body
  • In 1 place (localized) or widespread (diffuse)
  • Anywhere in the body, but most often in the neck and armpit

The dilated vessels may be:

  • Small (microcystic)
  • Large (macrocystic)
  • A mix of small and large (mixed cystic)

The affected area swells because fluid flowing through the abnormal lymph vessels slows or stops and extra fluid collects. Sometimes, LMs cause overgrowth of nearby tissues, like skin, muscle, fat or bone.

LMs can get bigger as your child grows. LMs may swell quickly and hurt when your child gets sick. The swelling slowly goes down after your child gets better.

Diagnosing an LM

Before birth, sometimes doctors diagnose an LM during a routine prenatal ultrasound exam. Our Fetal Care and Treatment Center can help your family and pregnancy care provider prepare for childbirth and plan your baby’s care.

After birth, doctors diagnose an LM by examining your child and looking at their medical history. To confirm the diagnosis, your child may have imaging studies or genetic testing. We have created a way to test patient tissue for genetic changes known to cause vascular anomalies. Genetic test results help inform your child’s diagnosis and may help guide treatment decisions.

The doctor may take pictures of the inside of your child’s body with:

  • MRI (magnetic resonance imaging)
  • Ultrasound
  • CT (computed tomography) scan

These images help us:

  • Confirm the diagnosis
  • Show the extent of the VM
  • Plan procedures
  • Find out what is causing symptoms
  • Track how an LM is changing

Problems That LMs May Cause

LMs are prone to bleeding and infection. They may cause overgrowth of nearby tissues, like skin, muscle, fat or bone. Other problems may happen, depending on the area of the body that is affected. LMs in the:

  • Skin can leak fluid and cause an infection of tissue in and under the skin (cellulitis).
  • Windpipe (trachea), tongue or chest can make it hard to breathe or eat.
  • Stomach and intestines (gastrointestinal tract) can cause protein loss.
  • Chest can leak lymph fluid into the chest cavity or cause heart and lung problems.
  • Belly can cause lymph fluid to leak into the abdomen.
  • Face may swell and become disfigured.
  • Bone can destroy bone and cause pain. When an LM harms nearby bone, it is called Gorham-Stout disease.

Treating an LM

The best treatment for your child depends on the location and size of their LM and whether it causes problems. We watch your child closely and recommend the right treatment at the right time. Options include:

  • Sclerotherapy

    We use sclerotherapy (SCLAIR-oh-THAIR-uh-pee) to reduce the size of an LM by blocking unneeded veins.

    First, an interventional radiologist uses ultrasound guidance to pinpoint the unneeded veins. Then a doctor injects a chemical that blocks blood flow and makes the veins collapse.

    Sclerotherapy may cause scarring. In some cases, the LM may not shrink or it may come back.

    Read more about sclerotherapy (PDF).

  • Surgery to remove the LM

    Sometimes surgery to remove or reduce the size of an LM is the best option. We consider surgery based on your family’s wishes and whether the LM is:

    • Causing symptoms like pain or bleeding
    • Making it hard to see, breathe or move
    • Affecting other important functions
    • Disfiguring

    Surgery may not be possible if the LM is widespread or surrounds important body parts and organs.

    Some children need multiple surgeries over a period of time. Your child may have surgery as well as other types of treatment.

    Surgery causes scarring and may damage the body parts that the LM affects. Years after the surgery, lymph vessels may return at the site of a scar.

    We use facial nerve mapping to make surgery safer when removing LMs in the head. Before surgery, we use small electric pulses to map the exact location of the branches of the facial nerves. During the procedure, real-time feedback about nerve activity helps guide surgeons. The technique means shorter surgery time, with smaller cuts and near-zero risk of nerve injury.

  • Glue embolization surgery

    Our doctors were the first to use medical-grade Super Glue to make it safer and easier to remove the tangle of extra veins. This is called glue embolization surgery (GES).

    • Before the procedure, we give your child medicine so they sleep without pain (general anesthesia).
    • Watching on flat screens that show your child’s LM in real time, an interventional radiologist places the needle in exactly the right spot. This assures that only the abnormal vessels are injected with glue.
    • The glue hardens the LM without harming the tissue around it.
    • Using a low-dose CT scan, we make a 3-D image of the LM to guide surgeons during the delicate procedure.
    • Surgeons remove the LM, including the glue inside.
  • Laser surgery

    We use surgical laser therapy to treat some LMs, often with other types of treatment. Most children need multiple treatments spread over many months.

    Before laser surgery, we give your child medicine so they sleep without pain during the treatment (general anesthesia).

    Laser therapy may cause some tissue scarring or changes in the color of the skin in the area. These scars and color changes can sometimes be improved by cosmetic procedures.

  • Lymphedema therapy

    LMs can cause swelling (lymphedema) that hurts, increases the risk for infection or limits motion. To ease pain and help your child be more active, a certified lymphedema therapist will create a custom treatment plan for your child.

    We use complete decongestive therapy (CDT). There are 4 parts to CDT:

    • Skin care
    • Gentle massage to improve flow of lymph (manual lymph drainage)
    • Compression therapy
    • Exercise

    Read more.

  • Medicines

    LMs are sometimes managed with medicines. Some medicines treat symptoms like pain or bleeding. Other medicines treat LMs directly. Your healthcare team will watch your child closely while they are taking these medicines. Your doctor will discuss the benefits and risks of each medicine.

    Medicines that help manage LMs include:

    • Antibiotics.
    • Corticosteroids.
    • Aspirin.
    • Rapamycin (sirolimus). Our clinic was one of the first to offer sirolimus to patients.
  • Clinical trials

    For some children, genetic testing helps doctors identify the exact genetic cause of their LM. Such a precise diagnosis may expand treatment options to include drugs that target the overactive biological pathway causing the malformation. If this is the case for your child, our doctors will talk with you about the options and any research studies (clinical trials) that might be a good match.

  • Cellulitis treatment

    LMs that leak fluid into the skin may cause infection (cellulitis). If cellulitis keeps coming back, it can:

    • Cause pain
    • Change how the skin and body looks
    • Lead to a serious infection

    For a serious infection, your child will need antibiotics. We may also treat them with steroid therapy. Corticosteroids can lower inflammation in the LM.

Contact Us

If you have questions about a consultation or second opinion, email us or call 206-987-4606.

If you would like an appointment, ask your child’s primary care provider to refer you.

Providers, see how to refer a patient

Paying for Care

Learn about paying for care at Seattle Children’s, including insurance coverage, billing and financial assistance.

For Healthcare Professionals