Ethmoid Sinus Mucocele Manifesting as Acute Ophthalmoplegia and Ptosis Rapidly Exacerbated by COVID-19 Infection: A Case Report.

A sinus mucocele is a dilated, epithelial-lined cystic lesion containing encapsulated mucus. Although its etiology remains uncertain, secondary infection may transform it into a pyocele. A 68-year-old female presented with sudden-onset ophthalmoplegia, ptosis, and blurred vision during the acute phase of COVID-19 infection. Physical examination and imaging identified an ethmoid sinus mucocele causing significant orbital compression. The patient underwent urgent endoscopic marsupialization. Intraoperative findings revealed increased internal pressure within the mucocele. Postoperatively, her ocular motility and ptosis improved immediately, with a full recovery of visual acuity within two weeks. This case suggests that COVID-19-associated mucosal inflammation or immune dysregulation may lead to the rapid expansion of pre-existing asymptomatic mucoceles. Clinicians should consider mechanical sinus lesions in the differential diagnosis of acute cranial nerve palsies during COVID-19 infection to ensure timely surgical decompression.