Abdominal cystic lymphangioma is a benign (noncancerous) malformation of the lymphatic vessels in the abdomen. These vessels carry lymph, a fluid that contains white blood cells that fight infection, throughout the body. The severity of the condition and the associated features vary from person to person. When present, signs and symptoms may include abdominal pain, an increase in waist circumference, an abdominal mass, intestinal obstruction, and/or volvulus (a twisting of the intestines). The cause of abdominal cystic lymphangioma is poorly understood; however, scientists suspect that it is a congenital anomaly. Most cases are diagnosed in people with no family history of the condition. Treatment varies based on the severity of the condition. People with small malformations that do not cause any symptoms may simply be followed with regular imaging studies to monitor for progression. Some of these cases may resolve spontaneously without treatment. When necessary, surgical excision is often the treatment of choice since it is associated with the lowest risk of recurrence.. The disease is Monarch Disease Ontology identifier MONDO_0021726 (abdominal cystic lymphangioma). Also known as: abdomen cystic lymphangioma.