Macroglossia: a review of the condition and a new classification.

In studying macroglossia, no one has described normal tongue size or applied direct measurement to the pathologically enlarged tongue. Since macroglossia is primarily a condition that requires treatment on a symptomatic basis, definition of the problem in clinical terms is the most useful form for the practitioner. Based on published reports and our clinical experience, a classification scheme for macroglossia has been formulated. The concept of true macroglossia and relative macroglossia form a framework that categorizes acquired and congenital forms of tongue enlargement. True macroglossia exists when histologic abnormalities correlate with the clinical findings of tongue enlargement. Vascular malformations, muscular enlargement, and tumors are the most common forms of true macroglossia. Relative macroglossia includes those cases of apparent tongue enlargement in which the histology does not provide a pathologic explanation. Down's syndrome is a commonly quoted cause for tongue enlargement and is a form of relative macroglossia. The development of this classification system establishes an approach and common terminology on which therapy, research, and communication can be based.