Peripheral nerve tumors involving paranasal sinuses: a case report and review of the literature

Sinonasal fibrosarcomas, malignant schwannomas, and "Triton" tumors. A clinicopathologic study of 67 cases

BACKGROUND

Sinonasal fibrosarcomatous neoplasms are uncommon tumors and there are no previous studies of a large number of such cases. The clinical and histologic features of 67 fibrosarcomatous neoplasms of the nasal cavity and paranasal sinuses are reported.

METHODS

Multiple clinical and histologic parameters (including immunostain results) were analyzed to characterize the features important for histologic recognition of the tumors and for correlation with patient outcomes.

RESULTS

Some tumors could be classified as malignant schwannomas or malignant "Triton" tumors, but their behavior was similar to that of the fibrosarcomas. Histologically, most tumors were very low-grade malignant neoplasms; however, 22% of patients died of their tumors. Factors that correlated with death were mitotic rate (greater than 4 mitoses per 50 high-power fields), increased tumor cellularity, and male sex.

CONCLUSIONS

Many tumors originally were diagnosed as benign (by others), probably causing initial undertreatment of some patients. Proper recognition and histologic evaluation of the tumor are important to ensure the best therapy and optimal patient survival.

Intracranial extension of a naso-ethmoid schwannoma

A rare case of intracranial extension of a naso-ethmoid schwannoma is presented. Its subsequent removal with few sequelae confirmed the benign nature and good prognosis of the disease.

A rare cause of nasal obstruction: a solitary neurofibroma

This case represents a peripheral nerve sheath tumor as a cause of nasal obstruction. Nerve sheath tumors are relatively uncommon; however, most otolaryngologists will encounter them. These tumors develop from cranial and spinal nerve roots and from peripheral nerves. In total, approximately 25% to 44% of nerve sheath tumors occur in the head and neck region. Although the most important are cranial nerve tumors--the majority being acoustic neuromas arising from the vestibular nerve--they may also develop in the nasal cavity.

Nerve sheath tumors of the paranasal sinuses: electron microscopy and histopathologic diagnosis

Tumors of the nerve sheaths are very unusual. They occur with the highest frequency in the head and neck region, yet only 4% have been found to occur within the paranasal sinuses. Only 40 cases of nerve sheath tumors with direct involvement of the paranasal sinuses have been reported in the world's literature to date. Three new cases of neurofibroma not associated with Recklinghausen's disease and one case of a schwannoma of the frontoethmoid and maxillary sinuses are presented. The clinical, radiographic, and histopathologic features of these lesions will be discussed with emphasis on electron microscopy and immunohistochemical differentiation of these rare and often confusing lesions.

Neurilemmoma involving the maxillary sinus: a case report

A case is reported of a neurilemmoma arising from the maxillary sinus. Its aetiology, presentation, histology and treatment are discussed.

Malignant triton tumor of the nose and paranasal sinuses: a case study

A patient with sinonasal malignant triton tumor (ie, malignant schwannoma with rhabdomyoblastic differentiation) is described. In spite of its recurrence, the tumor has behaved as a slow-growing, locally aggressive, low-grade sarcoma for 3 years. This deviatory behavior is ascribed to well-differentiated nature and the primary exophytic-polypoid growth of the tumor.

Neurofibromas of the paranasal sinuses

Two cases of neurofibroma of the paranasal sinuses are presented. The tumours presented as space-occupying lesions and were treated by local excision. Histologically one was a typical neurofibroma, whilst the other showed some features of a schwannoma. The patients show no evidence of tumour recurrence at 18 and 6 months respectively.

Otorhinolaryngological manifestations of von Recklinghausen's disease in Nigerians

Otorhinolaryngological manifestations of 13 patients with von Recklinghausen's disease appearing at Lagos University Teaching Hospital over a five-year period have been studied. Among patients with ENT manifestations of the disease, the most common general features exhibited were cutaneous neurofibromas (100 per cent), headache (69.23 per cent) and pruritus (46.15 per cent). But the head and neck findings included external meatal canal stenosis (30.77 per cent), conductive deafness (30.77 per cent), nasal discharge (30.77 per cent), cranial nerve involvement (30.77 per cent) and disfigurement of the soft tissues of the face (30.77 per cent). Involvement of pinna (23.31 per cent), rhinolalia aperta (15.38 per cent), mental retardation (15.38 per cent) and pharyngeal swelling (7.69 per cent) also featured. Clinically detectable bilateral acoustic neurofibromas in adults or astrocytomas in children were not found in this series. Involvement of the frontoparietal bone (7.65 per cent) presented with skull bossing which had to be differentiated from that due to sickle cell disease in the African. There was also a singular case of phrenic nerve involvement. However, malignancy occurred in one (7.69 per cent) of these patients. Thus, it is important always to follow-up these patients closely so as to detect malignant transformation in time.

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.

Management of paranasal sinus schwannomas

Schwannomas arising in the nasal cavities and paranasal sinuses are rare entities, with only sporadic cases appearing in the world literature. The lesion most commonly arises in the ethmoid and maxillary sinuses, with two cases having been reported in the sphenoid sinus. There are no reported cases of frontal sinus schwannoma. Four illustrative cases are presented which demonstrate the clinical features. The radiological investigation should include plain films and anteroposterior and lateral polytomography. Computerized tomography appears to be useful in planning surgery. An operative approach is approach is proposed which emphasizes a meticulous and complete removal of the lesion with preservation of adjacent structures and repair of any resultant dural defect.

Peripheral nerve sheath tumors of the paranasal sinuses

Only 4% of peripheral nerve sheath tumors of the head and neck occur in the paranasal sinuses. The most commonly involved sinus is the maxillary antrum and the most common histologic type is benign schwannoma. Two new cases of schwannoma occurring in the sphenoid and maxillary sinuses are reported. The clinical pathologic, and radiographic features of these lesions are reviewed.