Frontoethmoidal mucocele presenting as proptosis.

To cite: Shang Kuan W-C, Chi C-C. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013202733 DESCRIPTION A 34-year-old man suffered from itching, burning and a foreign body sensation in his left eye for 6 months prior to his first ophthalmology clinic visit, where eye drops were prescribed for presumed keratitis without obvious improvement. Furthermore, his left eyelid was erythematous and swelling and tearing subsequently developed in the following 3 months. Aspiration and irrigation were performed at another clinic with short-term symptom relief. However, diplopia, visual impairment of the left eye and headache occurred in the past month, and he was referred to the local hospital for treatment. According to the previous medical history of chronic paranasal sinusitis following functional endoscopic sinus surgery, at our hospital on 26 July 2004, he was referred to our department for further evaluation. There was no systemic disease or trauma history, contact lens use or contaminated water exposure, and he denied symptoms of nasal obstruction, purulent discharge or anosmia. An ocular examination showed periorbital chemosis, oedema, exophthalmos, hypertelorism and ophthalmoplegia (figure 1A). Sinuscopy showed mild mucoid discharge over the left middle meatus. CT on 4 October 2013 revealed an expansile cystic lesion in the left anterior ethmoid and frontal sinus areas, with adjacent bony erosions and extension into the left medial and retrobulbar areas, favouring a mucocele (figure 2). Considering the rapid progression of symptoms and visual acuity loss, a revision endoscopic sinus surgery was performed for orbital decompression. The patient is currently receiving regular follow-ups with dramatic improvements compared with his initial presentation (figure 1B). Learning points