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. Most cases are diagnosed in people with no family history of the condition.