Giant Sinonasal Osteoma with Orbital Extension; Endoscopic De-cavitation Technique; A Case Report

Osteomas are the most common benign tumors of the paranasal sinuses (PNS). While typically asymptomatic and managed conservatively, a minority become symptomatic, requiring surgical intervention. Giant osteomas (arbitrarily defined as >3cm) are rare, and their management can be challenging due to their size and extensive involvement. We report a 48-year-old woman presenting with a two-year history of progressive left-sided nasal obstruction. Computed tomography (CT) imaging identified a giant bony mass originating from the ethmoid sinus, with significant erosion into the medial orbital wall, skull base, and nasal floor. The patient underwent endoscopic sinus surgery for resection. The patient experienced complete resolution of her symptoms post-operatively, with no complications or evidence of recurrence at follow-up. This case demonstrates that even giant, extensively erosive ethmoid sinus osteomas can be successfully and safely managed via a purely endoscopic approach. This report adds to the limited literature on giant osteomas and supports the role of endoscopic surgery as a viable first-line intervention for such complex cases.