Macroglossia is the medical term for a large or enlarged tongue. It may be due to a variety of congenital and acquired conditions. Isolated macroglossia has no determinable cause. It is seen commonly in Down syndrome. The most common causes of tongue enlargement are vascular malformations (e.g. lymphangioma or haemangioma) and muscular hypertrophy. It may, however, be due to infiltration, as with primary systemic amyloidosis.