Cystic Hygroma

Cystic hygromas are benign tumors that appear as a fluid-filled sac, often forming on a newborn’s neck. The cyst forms because of a lymphatic system blockage, which causes fluid to build up under their skin. These cysts can be life-threatening and could lead to miscarriage or stillbirth. Treatment reduces the size of the cyst or removes it.


A cystic hygroma is a fluid-filled bump that forms on a baby’s neck caused by a blockage in the lymphatic system pathways.
A cystic hygroma is a fluid-filled bump that forms on a baby’s neck caused by a blockage in the lymphatic system pathways.

What is a cystic hygroma?

A cystic hygroma is a fluid-filled sac (cyst) that forms most often on your baby’s neck due to a malformation or blockage of the lymphatic system. The lymphatic system is a group of tissues and organs that move lymph fluid (a watery fluid full of white blood cells) through your bloodstream and circulatory system to remove waste and toxins.

Cystic hygromas can appear during pregnancy on an ultrasound or after your baby is born as a bump or bulge under their skin. If the hygroma appears during pregnancy, there is a risk of miscarriage or stillbirth.


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Who does a cystic hygroma affect?

A cystic hygroma could affect any baby since it may be the result of a genetic change that affects how the lymphatic system forms during fetal development. Cystic hygromas can occur on their own or among children diagnosed with a genetic condition like Down syndrome, Turner syndrome or Noonan syndrome.

Cystic hygromas could also form in adults after physical trauma or a respiratory infection.

How common is a cystic hygroma?

Cystic hygromas are rare and account for only 6% of all non-cancerous (benign) tumors during early childhood. Adult cystic hygromas are extremely rare.


Symptoms and Causes

What are the symptoms of a cystic hygroma?

Symptoms of a cystic hygroma vary based on the size and location of the fluid-filled sac (cyst). Symptoms could include:

  • A bulge under the skin.
  • Skin over the cyst has a blue tint.
  • The cyst is soft.
  • The cyst most often appears on the neck, but it can form anywhere on the body.
  • Size ranges from a grape to grapefruit and could increase in size as the baby grows.

Severe symptoms of a cystic hygroma include:

  • Physically disfigure part of the body.
  • Bone or organ damage.
  • Feeding difficulties.
  • Difficulty breathing (airway obstruction).
  • Hemorrhage.
  • Infection.

If a cystic hygroma is present during pregnancy, there is a risk of miscarriage or stillbirth due to complications from the cyst affecting how the fetus develops and grows. The cyst could create an excess amount of fluid in the fetus’ body (hydrops), which could cause early death.

What causes cystic hygroma?

The exact cause of a cystic hygroma is unknown. The cyst forms as a result of damage to the lymphatic system during fetal development, or as a result of physical trauma or respiratory infection in cases that affect adults. Damage to the lymphatic system causes lymph fluid to collect under the skin instead of flowing through your bloodstream, causing a bulge or sac-like growth of fluid.

Studies suggest that cystic hygromas could be the result of environmental factors like smoking or drinking alcohol during pregnancy. Other studies suggest that genetic changes or mutations that affect the development of the lymphatic system cause cystic hygromas.

Often, cystic hygromas form on their own, but some form in combination with genetic conditions like Down syndrome, Turner syndrome or Noonan syndrome.


Diagnosis and Tests

How is cystic hygroma diagnosed?

Diagnosis of a cystic hygroma occurs before your child reaches two years old. During pregnancy, a cystic hygroma diagnosis is possible with a routine prenatal ultrasound. A blood test to detect alpha-fetoprotein between 15 to 20 weeks helps confirm the diagnosis.

If prenatal tests suggest that your child has an abnormal number of chromosomes, your child may have a predisposition to cystic hygromas and your provider will carefully monitor the development of your fetus to make sure it is healthy.

After your baby is born, a physical examination of the cyst, along with an X-ray, ultrasound or an MRI will help your provider confirm the diagnosis and offer a treatment plan unique to your child’s condition.

Management and Treatment

How is a cystic hygroma treated?

Treatment is unique for each child diagnosed with a cystic hygroma. Your provider’s goal to treat the cyst is to remove it, if possible. Treatment options could include:

  • Surgery to remove the cyst.
  • Draining fluid from the cyst (percutaneous drainage).
  • Rerouting the cyst’s fluid through the body (sclerotherapy).
  • Removing the cyst with a laser (laser therapy).
  • Shrink the size of the cyst (radiofrequency ablation).

In some cases, no treatment is necessary because the cyst could go away on its own. In other cases, the cyst could return after treatment if there is damage to the lymphatic system. The success of treatment varies and is most often positive if your surgeon can remove all of the excess and abnormal tissue from the cyst.

Are there complications of the treatment?

There is a possibility of scarring after surgical treatment, which is dependent on the size and location of the cyst. There are treatment options that are less invasive than traditional surgery, which produce less scarring like laser therapy.

Treat your child’s cyst like a wound, especially if your child is healing from surgery. There is a risk of infection with any treatment, so monitor the cystic hygroma and make sure it isn’t leaking clear or yellow pus, changing color or size or is warm or tender to the touch. Contact your provider if you suspect your child has an infection.


How can I prevent a cystic hygroma?

It's difficult to prevent a cystic hygroma since the cause is unknown. Take steps to make sure your developing child is healthy by:

  • Getting a genetic test in consultation with your health provider before you become pregnant to understand your risk of having a child with a genetic condition.
  • Not smoking or drinking alcohol during pregnancy.
  • Attending regular checkups during your pregnancy to monitor the health of your developing fetus.
  • Eating a well-balanced diet and staying healthy.

Outlook / Prognosis

What can I expect if I have a cystic hygroma?

The prognosis is dependent on when your provider diagnoses the cystic hygroma, whether the cyst is the result of an underlying condition and the location and size of the cyst.

Surgery to remove the cyst leads to a good prognosis if your surgeon can safely remove excess tissue within the cyst. If your surgeon is unable to safely remove the excess tissue surrounding the cyst, there is a 15% chance that the cyst could return.

Early diagnosis and treatment lead to the best outcome and reduce your child’s risk of developing complications from the cyst, like organ damage and cosmetic abnormalities.

There is an increased risk of miscarriage and stillbirth in cystic hygroma cases that form in combination with chromosome abnormalities like Down syndrome. Your healthcare provider will monitor the progress of your developing fetus to make sure it is healthy during your pregnancy.

Living With

When should I see my healthcare provider?

Visit your healthcare provider if you notice your child’s cyst:

  • Size increases.
  • Changes color.
  • Leaks a yellow or clear fluid.
  • Is red, tender or warm to the touch.
  • Causes pain and discomfort.
  • Prevents your child from eating.

If your child has trouble breathing, call 911 or visit the emergency room immediately.

What questions should I ask my doctor?

  • Does my child need surgery to remove their cyst?
  • Did the cyst cause any organ, bone or nerve damage?
  • What are the side effects of the treatment you suggest?

A note from Cleveland Clinic

It may be alarming to see your newborn child with a large growth on their neck. Your healthcare provider will offer the best treatment for your child to make sure the cyst reduces in size or can be safely removed. Since cystic hygromas can relate to other genetic conditions, if you plan on becoming pregnant and want to understand your risk of having a child with a genetic condition, talk to your provider about genetic testing. If you're at risk of having a miscarriage or your baby is stillborn, your provider can offer resources or guidance to help you cope with a loss.

Medically Reviewed

Last reviewed on 03/15/2022.

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