lymphangioma /limfan′jē·ō″mə/ pl. lymphangiomas, lymphangiomata [L, lympha + Gk, angeion, vessel, oma, tumor] , a benign yellowish-tan tumor on the skin, composed of a mass of dilated lymph vessels. The tumor may be removed by excision or electrocoagulation for cosmetic reasons. Also called angioma lymphaticum. Compare hemangioma.