This results from chronic infection of one of the paranasal sinuses which becomes blocked and converted into a fluid filled cyst. This enlarges and expands into the orbit, where it frequently produces proptosis.
Sinus enlargement with erosion of the bony orbital wall is seen on plain X-ray. A CT may be necessary to differentiate the mucocele from a dermoid cyst.
Treatment is by surgical removal of the cyst and the re-establishment of nasal drainage.
Last reviewed 01/2018