A patient develops mucocele of the frontal sinus expanding into the orbit causing proptosis and diplopia. What is the pathophysiology of mucocele formation and the preferred treatment?

• A Retention cyst from blocked mucous gland duct; aspiration via transnasal puncture
• B Obstruction of the sinus outflow tract causing progressive expansion of mucus-filled cyst lined by sinus mucosa; endoscopic marsupialisation ✓
• C Malignant transformation of benign polyp causing bone erosion; total excision with margins
• D Inflammatory pseudocyst from antral mucosal oedema; spontaneous resolution or Caldwell-Luc

Explanation

A mucocele forms when chronic obstruction of sinus outflow causes progressive accumulation of mucus secretions, expanding to fill and eventually erode surrounding bone. The cyst is lined by respiratory epithelium (the native sinus mucosa) and contains mucus or mucoid fluid. Frontal mucoceles may erode through the orbital plate, causing proptosis, diplopia, and chemosis. The preferred modern treatment is endoscopic marsupialisation — creating a wide communication between the mucocele and the nasal cavity — which is as effective as open surgery with lower morbidity and recurrence rates.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.