Frontoethmoidal mucocele causing proptosis and visual loss

Mucoceles are benign mucus-containing cysts formed due to the obliteration of sinus ostium. They are most commonly found in the frontal sinus. Mucoceles can spread both intraorbitally and intracranially causing complications such as meningitis, brain abscess, and loss of vision. Radiological investigations are required for diagnosis, with both computed tomography (CT) and magnetic resonance imaging (MRI) being useful. Surgical approaches for management have changed from external to endonasal these days. We report a case where a 54-year-old patient presented to us with a 14 days' history of loss of vision and complete closure of eyes over 2 days. Contrast-enhanced CT scan and MRI confirmed the diagnosis of frontoethmoidal mucocele breaching the left frontal sinus floor. Endoscopic orbital decompression with functional endoscopic sinus surgery was done. Eye movements and ptosis recovered completely after the surgery, but the vision did not. Although the etiology of mucocele is multifactorial, obstruction of sinus ostium is the most plausible cause. Increasing pressure on adjacent structures by the expanding mucocele can cause intraorbital and intracranial complications. MRI is superior to CT in differentiating mucocele from soft-tissue neoplasms, although CT gives a more detailed information on bone structure. Endoscopic approaches have become the most preferred way to access frontoethmoidal mucoceles, with external approaches being reserved for mucoceles in certain inaccessible locations. Timely intervention is imperative to prevent undesirable complications.