Delayed development of frontal mucocele after fronto-orbital advancement in a child with craniosynostosis.

BACKGROUND: Sinus mucoceles rarely develop as a consequence of inadequate sinus ventilation that arises due to inflammation, allergy, polyps, tumors, surgery, and trauma. The development of frontal sinus is delayed until older than 6 years. Therefore, the development of the mucocele in the frontal sinus after fronto-orbital advancement surgery in young children with craniosynostosis may provide essential information for the development of the frontal sinus. CASE DESCRIPTION: We report a rare case of a 22-year-old man presenting with a frontal mucocele manifested by dull headache, proptosis, and diplopia, and which developed 16 years after fronto-orbital advancement surgery for craniosynostosis. Magnetic resonance imaging demonstrated that a multiple cystic mass extended from the frontal sinus to the retro-orbital space along the optic nerve. During surgery, we found that the cyst consisted of mostly thin, yellow mucosa, which developed from an anomalously overdeveloped frontal sinus containing yellow pus-like intracystic fluid. There was no gross local invasion by the cyst. We easily dissected and removed the mucosal cyst from the large frontal sinus completely with frontal sinus obliteration. We cranialized the anomalously large frontal sinus by removal of the posterior wall of the frontal sinus and then widening the ethmoidal drainage with endoscopic ethmoidectomy.
CONCLUSION: We report the first case of a frontal sinus mucocele that developed after fronto-orbital advancement surgery in the literature and suggest that the mucocele development after fronto-orbital advancement supports the hypothesis of frontal bone-inducing role in frontal sinus development.