Laterally located mucocele in a hyperpneumatized frontal sinus causing exophthalmos: A total endoscopic approach

Frontal sinus mucoceles are mucous secretory lesions within the sinus, presenting a slow – growing pattern, mostly behaving like a space-occupying mass with subtle symptoms until a bone erosion of the surrounding structures takes place. Intracranial and intraorbital expansion are regarded as the most considerable complications, demanding adequate surgical management in order to avoid recurrence. Endoscopic drainage is thought to be the current treatment of choice, with external approaches or combined approaches being considered for more severe cases where anatomy and disease extension restricts adequate endoscopic visualization of the lesion. We present a case of a 31-year-old female patient with a left frontal sinus mucocele, demonstrating with an unusual lateral frontal expansion and orbit invasion, causing exophthalmos and ophthalmoplegia. She was adequately managed by a Draf III endoscopic procedure achieving wide marsupialization and enough drainage of the mucocele. No sign of recurrence was noticed during the last 6-month follow-up. Giant mucoceles of the frontal sinus are a rare pathology. To our knowledge, endoscopic endonasal approach is a treatment modality that can provide an adequate drainage pathway, thus resulting in optimal clinical outcomes, compared with external approaches. Keywords: Frontal sinus; Mucocele; Exophalmos; Pneumosinus dilatans; Pneumocele.