Lymphangioma progress slowly and may invade local tissue REF: Sabiston 18th ed chapter 69 Lymphangioma are the lymphatic analogue of the Hemangioma of blood vessels. They are generally divided into two types: (1) simple or capillary lymphangioma and (2) cavernous lymphangioma or cystic hygroma. They are thought to represent isolated and sequestered segments of the lymphatic system that retain the ability to produce lymph. As the volume of lymph inside the cystic tumor increases, they grow larger within the surrounding tissues. Most of these benign tumors are present at bih, and 90% of them can be identified by the end of the first year of life. The cavernous lymphangioma almost invariably occur in the neck or the axilla and rarely in the retroperitoneum. The simple capillary lymphangioma also tend to occur subcutaneously in the head and neck region as well as the axilla. Rarely, however, they can be found in the trunk within the internal organs or the connective tissue in and around the abdominal or thoracic cavities. The treatment of lymphangioma is surgical excision, taking care to preserve all normal surrounding infiltrated structures. Lymphangiosarcoma is a rare tumor that develops as a complication of long-standing (usually more than 10 years) lymphedema. Clinically, patients present with acute worsening of the edema and appearance of subcutaneous nodules that have a propensity toward hemorrhage and ulceration. The tumor can be treated, as other sarcomas, with preoperative chemotherapy and radiation followed by surgical excision, which usually takes the form of radical amputation. Overall, the tumor has a poor prognosis