Cystic Hygroma in Children: Diagnosis and Treatment

How are cystic hygromas diagnosed in children?

Cystic hygroma can be diagnosed prenatally during an ultrasound. At around the tenth week of pregnancy, the baby may appear with excess fluid at the back of their neck. This will show up on the ultrasound as a clear space known as the “increased nuchal fold,” “nuchal lucency,” or “nuchal thickness.” At 15-20 weeks of pregnancy, a blood test can also determine whether the baby has cystic hygroma. This test measures the alpha-fetoprotein in the mother’s blood; high levels could indicate the presence of cystic hygroma.

Doctors will monitor the hygroma using ultrasound every three to four weeks. In these ultrasounds, the doctor will also watch if they develop hydrops, a buildup of extra fluid in the baby’s body that could result in miscarriage.

In preparation for birth, doctors recommend that you plan to deliver at a major medical facility in case of complications. Medical professionals may have the mother deliver via Cesarean section if hydrops are present or if the hygroma is large enough to prevent the head from passing through the birth canal. In rare cases, the baby’s karyotype is normal and the cystic hygroma is small enough to resolve itself during pregnancy. From there, the baby can be born healthy at full term.  

How are cystic hygromas treated in children?

Cystic hygromas cannot be treated while the baby is still in the womb.

Following birth, the baby will be monitored closely to ensure that they can breathe normally. Small cystic hygromas can disappear by themselves, but the majority of these cysts grow to be very big, sometimes larger than the baby’s head. Cystic hygromas grow faster when they are infected or bleeding on the inside. They will need to be treated as soon as possible to ensure that the baby does not suffer any further complications as they grow older.

Surgery: If a neonatologist recommends surgery, this will require an overnight hospital stay to remove the cyst.

Sclerotherapy: This 30-minute outpatient procedure is often used as treatment after surgery for recurrences or small areas of residual disease. First, the baby will be placed under general anesthesia. Then, using ultrasound, a radiologist will place a thin needle into the cyst. From there, they will inject medicine that shrinks lymphatic vessels. Some sclerosing agents include bleomycin, ethanol, and doxycycline. Unlike surgery, there is no incision being made so the baby will not have a scar. These methods are more effective when treating larger growths because there are more lymphatic vessels to shrink.

Cystic hygroma surgery risks and recovery

During surgery, babies risk damage to facial nerves and blood vessels. Following the procedure, the wound may become infected. Hemorrhage and lymphatic discharge are possible. Even after supposedly complete removal of the cyst, it is still possible for it to grow back. Even with these risks, many doctors prefer surgery as their first approach to treatment over sclerotherapy, especially if the lesion is small and easy to remove.