[Voluminous mucocele of frontal sinus with superior eyelid and orbit expansion]

A mucocele is an unusual benign cystic tumor, frequently seen in the adult and affecting mucous sinuses that expand the orbit by bone destruction. It is caused by a lack of sinus aeration; surgical treatment consists in cyst extirpation and sinus drainage.

A 72-year-old man, without a history of sinus disease, presented a voluminous mucocele of the right frontal sinus that had begun 3 years before, with superior eyelid and orbit expansion hiding and pushing the eye to the downside and the outside. The cyst was surgically removed via the external approach without sinus drainage because of a lack of technical means resulting from the total destruction of the anterior and severe thinning of the posterior wall of the right frontal sinus with dura mater exposure. After surgery, the patient recovered visual function without diplopia, and normal eyelid and ocular motility. However, the right eye is abnormally sized a bit downside.

A mucocele of the frontal sinuses can show major superior eyelid development with a low risk of trochlea injury during surgery, a possibility particularly if the destruction of the anterior wall of the frontal sinuses is opened ahead of the orbit septum. Sinus drainage was not undertaken for our patient because of the substantial destruction of the posterior wall of the frontal sinus, with a high risk of infection.