Definition of Cystic hygroma:
A cystic hygroma is a sac-like structure with a thin wall that most commonly occurs in the head and neck area.
Causes, incidence, and risk factors:
A cystic hygroma is a birth defect. It occurs as the baby grows in the womb from pieces of material that carries fluid and white blood cells. Such material is called embryonic lymphatic tissue. After birth, a cystic hygroma usually looks like a soft bulge under the skin. The cyst can't be seen until after birth, and sometimes is not noticed until the person is older.
