A cystic hygroma is a thin-walled, sac-like structure filled with lymph. It occurs most commonly in the head and neck area and often appears as a soft bulge under the skin.

This condition is a congenital (present before birth) abnormality caused by embryonic lymphatic tissues. Cystic hygromas are abnormal growths arising from these tissues.

A common symptom is a neck mass noted at birth, or discovered later in an infant after an upper respiratory tract infection.

• Chest X-ray
• Ultrasound
• CT scan

Treatment involves complete removal of the abnormal tissue whenever possible. However, cystic hygromas can often invade other neck structures, making this impossible. In these cases, other treatments have been attempted with only limited success. These include injection of sclerosing agents, steroids, chemotherapy agents, and radiation therapy.

The outlook is good if surgery can totally remove the abnormal tissue. In cases where complete removal is not possible because of involvement of neighboring nerves or blood vessels, recurrence is common.

Bleeding, infection, recurrence of the cystic hygroma, and damage to structures in the neck caused by surgery.

Call your physician regarding any neck mass found in a child or adult.