A cystic hygroma is a growth that often occurs in the head and neck area. It is a birth defect.
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.
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
The following tests may be done:
- Chest x-ray
- CT scan
- MRI scan
If the cystic hygroma is detected during a pregnancy ultrasound, other ultrasound tests or amniocentesis may be recommended.
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
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.
Complications may include:
- Damage to structures in the neck caused by surgery
- Return of the cystic hygroma
When to Contact a Medical Professional
If you notice a lump in your neck or your child's neck, call your health care provider.
Richards DS. Obstetric ultrasound: imaging, dating, growth, and anomaly. In: Gabbe SG, Niebyl JR, Simpson JL, et al, eds. Obstetrics: Normal and Problem Pregnancies. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 9.
Rizzi MD, Wetmore RF, Potsic WP. Differential diagnosis of neck masses. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology: Head & Neck Surgery. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 198.
Tower RL, Camitta BM. Abnormalities of lymphatic vessels. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 489.