Objective: Schwannomas are benign tumours arising from Schwann cells of the peripheral nerve sheath. They are relatively frequent in the head and neck region (25-45%) but rarely involve in the sinonasal tract (4%). The authors outline the diagnostic difficulties and the problems in choosing the best surgical approach in two atypical cases of sinonasal Schwannomas.
Methods: In the first case reported clinical data, sex and age of the patient, nasal endoscopy and angio-MRI led us to suspect an angiofibroma; therefore, we approached the case without a biopsy performing a preoperative selective embolization followed by an endoscopic resection. In the second case, due to initial visual symptoms and to the ethmoid-orbital compartment involvement, we performed a sinonasal endoscopy and collected a biopsy which resulted to be fundamental in the diagnostic assessment. Tumour excision was then obtained throughout an intracranial/endonasal approach.
Results: The two presented cases revealed the presence of cystic Schwannomas. In the first case, diagnosis was made only post-operatively after histological examination. Patients underwent complete surgical excision by means of an endoscopic sinonasal approach, in the second case associated to a left frontal craniotomy. The patients showed no signs of recurrence at a 9 months follow-up.
Conclusions: Nasal endoscopy was extremely important in making the diagnosis, allowing an accurate assessment of the tumour extension and a biopsy. The diagnosis of sinonasal Schwannomas remains challenging; sometimes, clinical behaviour and modern imaging may be misleading. The diagnostic and therapeutic importance of sinonasal endoscopy is emphasised in the two presented cases.