[Ethmoidal mucocele in a nursing infant. Apropos of 1 case].

Characteristic features of mucoceles of the paranasal sinuses in infants are their extreme rarity, their localization exclusively in the ethmoidal sinuses, and the specific nature of their clinical expression. Partial explanation of these specific features is provided form knowledge of the embryology of the facial sinuses and the various pathogenic theories developed concerning these mucocele lesions. Two out of four cases observed were associated with viscidosis, and a sweat test must be routinely performed in all cases.