Extragnathic Sinonasal Ameloblastoma: A Rare Benign Intranasal Tumor with Malignant Features

Abstract

Objective: To report a case of extragnathic sinonasal ameloblastoma and discuss its clinical features, approach to diagnosis, pathology, and management.
 
 Methods:
 Study Design: Case report
 Setting: Tertiary government university hospital
 Subject: One
 
 Results: A 40-year-old female consulted for a rapidly enlarging right intranasal mass of 4 months duration associated with recurrent profuse epistaxis and nasal obstruction. Previous specimens of the mass were histopathologically interpreted as ameloblastoma versus craniopharyngioma. Examination revealed a pink, fleshy, smooth right intranasal mass with associated nasomaxillary bulge and supero-lateral displacement of the right eye. Computed tomography (CT) scan and magnetic resonance imaging (MRI) of the nasal cavity and paranasal sinuses demonstrated a soft-tissue density occupying the entire nasal cavity with erosion but no invasion of the maxillary sinus and no intracranial extension despite erosion of the skull base. The mass was completely excised via lateral rhinotomy and the final histopathologic diagnosis was ameloblastoma.
 
 Conclusion: Extragnathic sinonasal ameloblastoma is a benign but locally aggressive variant of ameloblastoma involving the nasal cavity and/or paranasal sinuses often mimicking malignant tumors. Diagnosis is primarily based on histopathology but radiologic and intraoperative findings help distinguish it from differentials. Complete surgical excision remains the treatment of choice, and coupled with good follow up, may improve the prognosis of patients.
 
 Keywords: sinonasal ameloblastoma, extragnathic, craniopharyngioma