Cystic Hygroma

Medically Reviewed by Amita Shroff, MD on November 28, 2022
3 min read

A cystic hygroma is a rare type of cyst that babies can get, usually in their head or neck, if their lymphatic system gets blocked while it’s growing. (This system helps filter out harmful things, including germs.) Doctors often find cystic hygromas before a baby is born.

Only one in 8,000 babies is born with this kind of cyst. Some of them may also have certain birth defects. So if your baby has a cystic hygroma, your doctor will probably suggest tests to check for other problems. But some babies born with a cystic hygroma are healthy.

Sometimes these cysts go away on their own. If not, it’s important to get surgery to remove a cystic hygroma so it doesn’t harm nearby areas of the body, become infected, or make your baby uncomfortable as they grow.

Symptoms of a cystic hygroma depend on where and how big it is. The growth may make it hard for nearby organs and other body parts to work the way they should.

In newborn babies, a cystic hygroma looks like a bulge under the skin, which may be slightly blue. Babies born with this type of cyst often have a hard time eating and may grow more slowly than those without cystic hygromas. If a cystic hygroma is near the throat, your baby may have trouble breathing. These cysts can become infected. Left untreated, the cystic hygroma can harm nearby bones and teeth.

The cystic hygroma will get bigger as your baby grows, and it may grow quickly if the cyst becomes infected or there is bleeding inside it.

Both a baby’s genes and their environment in the womb can cause problems with the way their lymphatic system grows. This is how cystic hygromas form. It may happen on its own or with genetic conditions such as Turner, Down, or Noonan syndromes.

When adults get a cystic hygroma, it can be due to trauma or a past respiratory infection. But it’s often not clear what caused the cyst. It may even disappear during pregnancy.

When you’re pregnant, your doctor may find your baby’s cystic hygroma during a routine ultrasound. These cysts are usually found by the 20th week of pregnancy. You may also notice it after your baby is born or even later in your child’s life.

If you find out while you’re pregnant that your baby has a cystic hygroma, the doctor will probably recommend genetic testing to see if there are other problems. These can include: 

  • CVS (chorionic villus sampling). The doctor removes some of these wispy pieces of tissue from the placenta that share your baby’s genetic makeup.
  • Amniocentesis. The doctor tests a sample of your amniotic fluid to test for genetic conditions.

You’ll also have frequent ultrasounds to watch for changes in the cyst and any complications. 

The doctor will likely plan for you to give birth by C-section at 38 weeks. Find a hospital where you have access to both neonatal intensive care and pediatric surgeons. The doctor can help you choose one.

If your child has signs of a cystic hygroma after they’re born, they may get tests including chest X-ray, ultrasound, and an MRI or CT scan to diagnose the cyst.

Doctors use surgery to remove a cystic hygroma. If parts of it are left behind, there’s a 15% chance it will come back. Though they don’t work as well as surgery, there are other options, such as:

A cystic hygroma can cause you to make too much or too little amniotic fluid, which can put your unborn baby at risk. Many times, it causes a miscarriage. A baby born with a cystic hygroma can have other complications.

  • The mass may block your baby’s windpipe.
  • Your baby may develop facial deformities.
  • The cyst can lead to a skin infection called cellulitis.
  • Surgery to remove it can cause problems including nerve damage and heavy bleeding.
  • The cystic hygroma may grow back.

As a parent, you may want to get support through groups focused on this condition, such as the nonprofit Birth Defect Research for Children and the Lymphatic Education and Research Network.