Schwannomas or neurilemmomas are tumors of benign nerve sheath, and between 25 and 45% of all arise in the head and neck region. Less than 4 % are found in the sinonasal tract and their diagnosis may have difficulty due to non-specific symptoms and image characteristics. In several cases, complete surgical removal by endoscopic approach is the treatment of choice in these tumors. We report the management of an unusual case of sphenoid sinus schwannoma in a 70-years-old male along with massive bilateral nasal polyposis and severe symptoms. The association with severe sinonasal polyposis has not been previously described.Keywords: Schwannoma; Neurilemmoma; Sinonasal polyposis the III, IV and VI cranial nerves, in the autonomic nervous system, in the carotid plexus or sphenopalatine ganglion [1]. Whether sinonasal schwannomas can be derived from the olfactory nerve components is still a controversial issue [2], but recent studies point more likely to its origin in the meningeal or ethmoidal branches of the trigeminal nerve [3]. The most frequent locations in the sinonasal tract are: the ethmoidal sinus, maxillary sinus, nasal cavity and nasal septum. The sphenoid and frontal sinuses are rarely affected [1].The non-specific signs and symptoms of sinonasal schwannomas are the same of those of any mass of the anterior or posterior nasal tract [1], and their imaging findings are rather unspecific [4,5]. Differential diagnosis should be made with other more common skull base tumours or space-occupying mass lesions such as sphenoid mucocele, angiofibroma, inverted papilloma, clival chordoma, chondrosarcoma, meningioma, pituitary adenomas, craniopharyngiomas and plasmacytoma [4,5].Complete surgical excision is considered the preferred treatment and most lesions may be removed by standard endoscopic techniques [1,6,7], although different approaches must be done if intracranial extension is present [1,7].Here in we report an unusual case of sphenoidal schwannoma coupled with sinonasal massive polyposis, and we focus the role of computed tomography (CT) and magnetic resonance image (MRI) on the differential diagnosis and the surgical endoscopic approach. Case ReportA 70-year-old male was attended at the Emergency Department of our hospital, with nasal obstruction, hyposmia, severe headache, ocular pain and diplopia. He had medical history of arterial hypertension, deep venous thrombosis and nasal polyposis in treatment with hydrochlorothizide, acenocumarol and topical intranasal corticosteroids. There was no personal or family history of neurofibromatosis disease. The physical examination showed a VI left cranial nerve palsy. Noncontrast emergency CT revealed a complete sinonasal polyposis opacification with a 5 x 3.5 cm sphenoid sinus expansive lesion. There was no calcification or bone destruction (Figure 1).The initial suspicion was sphenoidal mucocele, and MRI was performed. The MRI showed an expansive mass of the 4.1 x 4.4 x 4.2 cm sphenoid sinus expansive mass, heterogeneous on T2 weighted images and isointense...