Nonepithelial tumors of the nasal cavity, paranasal sinuses and nasopharynx. A clinicopathologic study. XII: Schwann cell tumors (neurilemoma, neurofibroma, malignant schwannoma).

Twelve Schwann cell tumors (two neurilemomas, six neurofibromas, and four malignant schwannomas), arising in the nasal cavity, paranasal sinuses or nasopharynx, are described. Schwann cell neoplasms only rarely develop in this area. Clinically, these tumors lead to nonspecific symptoms including nasal obstruction epistaxis, facial pain and swellling, and proptosis, similar to those produced by other neoplasms that involve this area. On radiologic examination, a mass lesion may be identified. Benign Schwann cell tumors may lead to bone erosion, which thus is not necessarily a sign of malignancy. The correct diagnosis of Schwann cell tumor is usually made only when histologic sections are studied. The histologic differentiation between Schwann cell neoplasms and myxomas, fibroblastic tumors, fibrous histiocytomas and fibro-osseous lesions is discussed. Treatment depends upon the type of tumor. Neurilemomas, which usually are encapsulated neoplasms, can be treated by local excision. Neurofibromas may infiltrate extensively, and thus may require an extensive surgical resection; however, functional and cosmetic considerations should be taken into account because neurofibromas, even if incompletely excised, may recur clinically only after many years. Malignant schwannomas tend to be aggressive neoplasms, but because of the anatomy of the area, radical resections leading to complete removal of the tumor cannot always be carried out.