in the palate or the alveolar ridge. Middle ear effusion may indicate tumor involvement of the nasopharynx, Eustachian tube, pterygoid plates, or tensor veli palatini muscle. Extension to the skull base may lead to involvement of the cranial nerves resulting in anosmia, blurred vision, diplopia, or hypoesthesia along the branches of the trigeminal nerves. The presence of an associated mass in the neck may represent cancer metastatic to the cervical lymph nodes.
FIGURE 17.1 Endoscopic view of a tumor arising from the floor of the right nasal cavity. Biopsy revealed squamous cell carcinoma.
neuroectodermal tumors. The Schneiderian epithelium gives rise to Schneiderian (inverted) papillomas and carcinoma. Minor salivary gland tumors include adenoid cystic and mucoepidermoid carcinomas. Melanocytes within the nasal mucosa can give rise to sinonasal melanoma. Nonepithelial tumors arising from the sinonasal region include juvenile nasopharyngeal angiofibroma, hemangiopericytoma, sarcomas, and fibro-osseous lesions such as fibrous dysplasia, ossifying fibromas, and giant cell tumors. The differential diagnosis of sinonasal neoplasms is detailed in Table 17.1.
TABLE 17.1 Tumors of the Sinonasal Tract