Lymphatic malformations (LM), formerly referred to by the term lymphangioma, are malformations of the lymphatic system which result in obstructed lymphatic drainage. There are two types of LM: macrocystic LM (including cystic hygroma/lymphangioma) and tissue-infiltrating microcystic LM (lymphangioma circumscriptum). The macro and microcystic forms of LM may occur in association.