Introduction: Inverted papilloma is a benign epithelial neoplasm, originating from the Schneiderian membrane of the nose. It has a known propensity for recurrence, local aggressiveness, and association with transformation to squamous cell carcinoma.
Methods and Results: We report a 42-year-old Chinese male who underwent endoscopic excision of benign inverted papilloma of the right nose in 1995. Seven years later, he presented with a lesion involving the right ethmoids with intracranial extension. En bloc resection of the tumor was performed via a bicoronal approach with bifrontal craniotomy and extended lateral rhinotomy with medial maxillectomy. Intraoperative examination revealed that the intracranial part of the tumor was extradural with erosion of the roof of the right orbit. The frontal sinus was filled with inspissated mucus. The tumor also involved the ethmoidal air cells and superior turbinate. The postoperative histopathologic diagnosis was an inverted papilloma with focal areas of malignant transformation with mitotic figures. Postoperative recovery was uneventful and he underwent adjuvant radiotherapy.
Conclusion: We conclude that intracranial extradural inverted papilloma can be effectively controlled with craniofacial resection. Intracranial intradural involvement of inverted papilloma has a poor prognosis regardless of treatment. Aggressive treatment of intranasal inverted papilloma may be the most important factor in preventing intracranial presentation.
