Ethmoidal Mucocele Presenting as Oculomotor Nerve Paralysis
A previously healthy 56-year-old man presented with acute headache, ocular pain, and ptosis on the right side beginning one day prior to the visit (). The patient did not complain of deterioration of visual acuity or any nasal symptoms such as rhinorrhea, nasal obstruction, or hyposmia. The patient had no history of surgery or facial trauma, and the previous medical history was unremarkable.\nOn admission, vital signs were normal. General laboratory tests, including complete blood count, electrolytes, cholesterol, glucose, erythrocyte sedimentation rate, and chest radiography were normal. During the ophthalmological examination, visual acuity was 20/20 oculus uterque (OU). Confrontation visual fields were also normal. Pupils were equal at 4 mm OU with normal reactivity and no relative afferent pupillary defect. Ductions were full oculus sinister (OS). The oculus dexter (OD) would not adduct beyond the midline; supraduction and infraduction were diminished, but abduction was intact. Exophthalmometric, biomicroscopic, and ophthalmoscopic examinations showed normal findings. Weakening of muscle strength and sensory deterioration that may have suggested myasthenia gravis were not detected in neurological examinations. Serologic tests such as acetylcholine receptor antibody, rheumatoid factor, and antineutrophil cytoplasmic antibody were all negative.\nBrain magnetic resonance imaging and computed tomography (CT) documented no lesions on the brain or orbit. However, a mucocele was detected in the right posterior ethmoid sinus. It was located beside the apex of right orbit, and there was suspicious bony erosion but no dehiscence of the lamina papyracea on the CT images (). The nasal cavity appeared normal upon endoscopic examination.\nEndoscopic sinus surgery was performed under general anesthesia. After shrinking the turbinate mucosa with epinephrine-soaked gauze, an endoscopic examination was done with a 4-mm diameter, 0 degree nasal endoscope. The uncinate process and bulla ethmoidalis were serially resected with cold instruments under endoscopic view. Ethmoidectomy was performed through the third lamella to the posterior ethmoid sinus. At this point, the capsule of a mucocele with viscous mucus and yellow fluid with inspissated debris was found. There was no bone dehiscence on the lamina papyracea under the surgical field. Endoscopic marsupialization was performed. Headache and eyeball pain were noticeably reduced immediately after the operation. Improvement of ocular symptoms was observed at an outpatient clinic 2 weeks postoperatively and symptoms were completely resolved 4 weeks after operation. The patient has been followed for more than 30 months and with no recurrence of symptoms.