Cystic Hygroma is a medical condition that causes abnormal growths in the neck due to malformation of the lymphatic vessels. It is also known as hygroma colli and lymphangioma. There are several other synonyms for this condition. These include lymphatic malformation, cavernous lymphangioma, cystic lymphangioma, and macrocystic lymphatic malformation. Some other terms that may be used to describe this condition include congenital cystic lymphangioma, hygroma cysticum, and cystic lymphatic hamartoma. No matter what term is used, this condition can cause significant discomfort and health problems if left untreated. It is important to seek medical attention if you suspect you or a loved one may have cystic hygroma.