Definition

A cystic hygroma is a growth that often occurs in the head and neck area. It is a birth defect.

Alternative Names

Lymphangioma; Lymphatic malformation

Causes

A cystic hygroma occurs as the baby grows in the womb. It forms from pieces of material that carry fluid and white blood cells. This material is called embryonic lymphatic tissue.

After birth, a cystic hygroma most often looks like a soft bulge under the skin. The cyst may not be found at birth. It typically grows as the child grows. Sometimes it is not noticed until the child is older.

Symptoms

A common symptom is a neck growth. It may be found at birth, or discovered later in an infant after an upper respiratory tract infection (such as a cold).

Exams and Tests

Sometimes, a cystic hygroma is seen using a pregnancy ultrasound when the baby is still in the womb. This can mean that the baby has a chromosomal problem or other birth defects.

The following tests may be done:

• Chest x-ray
• Ultrasound
• CT scan
• MRI scan

If the condition is detected during a pregnancy ultrasound, other ultrasound tests or amniocentesis may be recommended.

Treatment

Treatment involves removing all of the abnormal tissue. However, cystic hygromas can often grow, making it impossible to remove all of the tissue.

Other treatments have been tried with only limited success. These include:

• Chemotherapy medicines
• Injection of sclerosing medicines
• Radiation therapy
• Steroids

Outlook (Prognosis)

The outlook is good if surgery can totally remove the abnormal tissue. In cases where complete removal is not possible, the cystic hygroma commonly returns.

The long-term outcome may also depend on what other chromosomal abnormalities or birth defects, if any, are present.

Possible Complications

Complications may include:

• Bleeding
• Damage to structures in the neck caused by surgery
• Infection
• Return of the cystic hygroma

When to Contact a Medical Professional

If you notice a lump in your neck or your child's neck, contact your health care provider.

References

Bell EB, Nugent A, El-Deiry MW. Differential diagnosis of neck masses. In: Flint PW, Francis HW, Haughey BH, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 113.

Kelly M, Tower RL, Camitta BM. Abnormalities of lymphatic vessels. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 516.

Marcdante KJ, Kliegman RM. Lower airway, parenchymal, and pulmonary vascular diseases. In: Marcdante KJ, Kliegman RM, eds. Nelson Essentials of Pediatrics. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 136.

Richards DS. Obstetric ultrasound: imaging, dating, growth, and anomaly. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Philadelphia, PA: Elsevier; 2021:chap 9.