Neurogenic tumors of the mouth and jaws

Tongue Schwannoma: A Clinicopathologic Study of 19 Cases

Schwannomas commonly occur in the head and neck but infrequently involve the oral cavity and rarely affect the tongue. The clinical and pathologic features of 19 cases of schwannoma arising in the tongue were analyzed. There were 13 males and 6 females ranging in age from 12 to 82 years (mean 34 years; median 29 years). The majority of tumors presented as an asymptomatic mass localized to the anterior two-thirds of the tongue. Histologically, 18 schwannomas exhibited characteristic Antoni A and B areas with the former pattern predominating. One tumor was composed exclusively of cellular Antoni A tissue and was classified as a cellular schwannoma. Tumor encapsulation was variable with nearly half of the lesions lacking a well-defined fibrous capsule. All were strongly and diffusely positive for S-100 protein. No recurrences were observed on clinical follow-up. Schwannoma of the tongue, although rare, should be separated from other types of lingual nerve sheath proliferations and tumors.

Oral peripheral nerve sheath tumors: A clinicopathological and immunohistochemical study of 32 cases in a Brazilian population

Background

Oral peripheral nerve sheath tumors (OPNSTs) are reactive or neoplastic diseases that develop from proliferation of the nerve itself or their limiting sheaths. Here we describe the clinicopathologic data of OPNSTs observed in a sample of the Brazilian population and evaluate the expression of molecules associated with neural biology to determine their usefulness in the diagnosis.

Material and Methods

Descriptive study of cases diagnosed as OPNSTs, from the Pathology Laboratory at the School of Dentistry/ Federal University of Uberlandia, followed by an immunohistochemical study of S-100, CD57, neurofilament protein (NFP) and epithelial membrane antigen (EMA).

Results

OPNSTs comprised 0.27% of all biopsies. There were eight patients with neurofibromas, eight with traumatic neuromas, seven with schwannomas, five with granular cell tumor (GCT), and four with palisaded encapsulated neuromas (PEN). Women were more frequently affected (60.6% of the cases). Tongue and lips prevailed as the most frequent sites. S-100 was reactive in 100% of the cases. Neural fibers evidenced by CD57 reactivity of their Schwann cells were always nested in bundles within neurofibromas and GCT, absent within schwannomas and dispersed within PEN. Reactivity for NFP was limited to axons and then followed the same pattern of CD57, though much less evident. Reactivity for EMA was observed in the capsular tissues and perineurium of nerve fascicles, and absent in parenchymal cells of GCT.

Conclusions

This study showed that OPNSTs are rare, widely benign and often found in tongue and lips. OPNSTs evolve from a common origin to distinct histological patterns, with eventual overlapping in their clinical and morphologic features. The arrangement of reactive residual neural fibers for CD57 can be a useful staining in the differential diagnosis of OPNSTs. Key words:Peripheral nerve sheath tumors. Oral cavity. Differential diagnosis. Immunohistochemistry. CD57 antigens.

Solitary Encapsulated Neurofibroma Not Associated with Neurofibromatosis-1 Affecting Tongue in a 73-Year-Old Female

Neurofibromas are benign tumors of nerve cell origin arising due to proliferation of Schwann cells and fibroblasts. They are usually asymptomatic and hence remain undiagnosed. They are commonly found on the skin and intraorally tongue is the most common site for their occurrence. Here, we present a unique case of solitary encapsulated neurofibroma in the oral cavity without any clinical manifestations or family history of Neurofibromatosis type 1 in a 73-year-old female patient who presented with a painless swelling on the tongue. The histopathologic findings closely mimicked benign fibrous histiocytoma. In our case, definitive diagnosis of neurofibroma was made based on clinical findings, family history, and histopathological and immunohistochemical evaluation. Through this case report we want to emphasize the role of biopsy and immunohistochemistry in arriving at a confirmatory diagnosis. The patient was treated by surgical excision and showed no signs of recurrence over a follow-up period of 12 months.

Neurofibroma of the palatal mucosa. A case report

Neurofibromas have not been reported in the periodontal literature. In this case report, a 27-year-old female presented with a complaint of a lump in the maxillary left palatal tissue; periodontal evaluation revealed a mass 15 x 8 x 4 mm on the palatal mucosa. After removal, the region healed without recurrence. The patient was referred to her physician for a physical, and no evidence of neurofibromatosis was found elsewhere, suggesting that this case represented an example of an isolated oral neurofibroma lesion.

Central neurilemmoma (schwannoma) of the mandible. Case report

A neurilemmoma presenting as a central bone tumour is uncommon with less than 40 cases having been reported in the jaws. A further case of intraosseous (central) neurilemmoma arising in the posterior mandible of a 55 year old Vietnamese woman is presented with discussion on the incidence, clinical presentation, radiographic appearance, histology and treatment of this benign neurogenic tumour.

Neurofibroma of the oral cavity

Neurofibromata are uncommon tumours of the oral cavity, and are seen either as solitary lesions or as part of the generalised syndrome of neurofibromatosis. A review of the literature is presented together with a case report of a solitary neurofibroma.

Neural tumors of the oral cavity. A review of the spectrum of benign and malignant oral tumors of the oral cavity and jaws

The clinical and histologic features of benign and malignant neural tumors of the oral cavity and jaws are reviewed. Some rarer histologic variants are mentioned. Particular attention is paid to the two syndromes involving neural tumors of the oral cavity, namely, neurofibromatosis and multiple endocrine neoplasia III. A previously unreported case of the latter is presented.

Neurofibroma and schwannoma of the oral cavity. A clinical and ultrastructural study

The clinical parameters of fifty-five cases accessioned as neurofibroma and schwannoma of the oral cavity were reviewed. An electron microscope study was performed on several cases. The component cells of neurofibroma were spindle shaped, with bundles of collagen fibrils between cells. Junctional complexes were observed between adjacent cells. Component cells of the schwannoma showed numerous convoluted cytoplasmic processes. Reduplication of basal lamina was frequently observed and formed the material in the hyalinized area of Verocay bodies.

Intraosseous neurofibroma of the jaws

Two cases of intraosseous neurofibromas of the mandible are presented. Only 25 cases of this tumor have been published previously. Of the present two cases, one was located at the upper border of the mandible, in the left second molar area where the tooth had been extracted 2 years previously. In the second case, the tumor presented itself as a 10 x 2 cm large destruction, mainly following the course of the alveolar nerve from the mandibular foramen to the mental foramen in the right side of the jaw. The mandibular first right molar was missing but the relationship between the extraction of the tooth and the development of the tumor could not be demonstrated. Histologically, the two tumors differed in the way that case 1 showed a conspicuous amount of delicate, wavy fibrils, some of which showed concentric lamellations resembling the pacinian corpuscle but without neurites containing nerve fiber bundles and also demonstrated a slight pleomorphism.

Central neurilemmoma of the jaws. Review of literature and case report

Neurilemmomas presenting as primary central bone tumors are extremely rare. Only 21 cases have been reported to have arisen in the jaws; all except for one have occurred in the mandible. The majority of these have been associated with the inferior dental nerve. A case of a central neurilemmoma arising in the anterior mandible is reported. Its probable origin is from one of the alveolar branches of the incisive nerve--an unusual site in the mandible. The radiographic features include expansion of cortical bone, resorption of roots of teeth, the presence of lace-like bony septa and a spotty calcification within the tumor. The treatment and the prognosis are briefly discussed.

Syndrome of multiple mucosal neurofibromas, pheochromocytoma and medullary thryoid carcinoma. Report of a case

The present article reports a case of multiple endocrine neoplasia (MEN) syndrome, type IIb, including the following components: pheochromocytoma, medullary thyroid carcinoma, hyperplastic corneal nerves and multiple mucosal oral and ocular neurofibromas. The patients, a 35-year-old male also exhibited a series of other pertinent findings, i.e. thickened eyelids, marfanoid habitus and widened mandibular canal and mental foramina. In the discussion the clinical and histopathologic characteristics of the present case are compared with similar findings in other previously published cases. The multiple oral mucosal neurofibromas are described clinically and histopathologically and are stated as a pathognomonic early sign of the syndrome.