Inverted Papilloma Originating Exclusively from the Sphenoid Sinus: A Rare Entity

Inverted Papilloma (IP) is a rare, benign but locally aggressive sinonasal tumour arising from the Schneiderian membrane, commonly originating from the lateral nasal wall and rarely from the sphenoid sinus alone. Exclusive sphenoid sinus involvement accounts for less than 2% of cases and may present with non specific or atypical symptoms, leading to delayed diagnosis. A 60- year-old male presented with intermittent right ear discharge, hearing loss, and mastoiditis without significant nasal complaints. Clinical evaluation revealed right-sided conductive hearing loss and features of chronic otitis media. Imaging showed right chronic otomastoiditis and near-complete mucosal thickening with hyperdensity in the left sphenoid sinus extending into the nasopharynx, raising suspicion of fungal or allergic rhinosinusitis. Endoscopic surgical intervention with excisional biopsy was performed. Histopathological examination demonstrated characteristic endophytic epithelial proliferation consistent with IP. Postoperative recovery was uneventful, and follow-up endoscopy showed satisfactory healing. Isolated sphenoid sinus IP is exceedingly rare and may present with atypical otologic manifestations. Early radiological evaluation and histopathological confirmation are essential for accurate diagnosis and timely surgical management due to the risk of recurrence and malignant transformation.