Anterior Ethmoid Mucocele Simulating Frontal Mucocele

Introduction: Sinus mucoceles are benign tumoral lesions lined with respiratory epithelium containing mucoid substance, affecting paranasal sinuses. They develop after obstruction of sinus drainage pathways by inflammatory, neoplastic, postoperative, or posttraumatic processes. It can expand and produce bone remodeling that can affect surrounding structures such as the orbit or the anterior skull base.

Objectives: This study aims to report a rare case of ethmoid mucocele invading almost entirely the frontal sinus. To show the effectiveness of the treatment performed endoscopically with immediate improvement of symptoms.

Resumed Report: A 51-year-old male patient (J. A. M.) with a history of 4 years of frontal headache associated with proptosis. Surgical treatment was proposed, and he underwent a hemicraniectomy 3 years ago without symptoms improvement. Two years ago he underwent another intervention, being performed a nasal endoscopic surgery, also without improvement. He attended to our service with a paranasal sinus tomography showing lesion, with soft tissue density, affecting much of the frontal sinus, however, a more detailed study proved that actually it was an anterior ethmoid cell occupying almost entirely the frontal sinus. The treatment was performed by nasal surgery with endoscopic approach, performing ethmoidectomy with full exposure of the skull base and marsupialization of the mucocele.

Conclusion: Nasal endoscopic marsupialization has been showed as a safe and effective procedure in the therapeutic approach of ethmoidal mucocele. The procedure should be instituted as soon as diagnosis is made.