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

Intraoral neurofibroma: A case report with emphasis on immunohistochemical markers

ABSTRACT

A neurofibroma is a benign peripheral nerve sheath tumor. They occur in combination with neurofibromatosis or as a solitary mass. Intraoral neurofibromas pose diagnostic difficulties, suggesting the appropriate use of diagnostic markers and clinical knowledge. Here, we report a case of intraoral neurofibroma in a 57-year-old female who reported with the complaint of painless growth in the lower left back tooth region for the past three years. Based on the clinical features, provisional diagnosis of traumatic fibroma was made. However, histopathology proved it to be a benign spindle cell lesion; upon further investigation by immunohistochemistry, it was diagnosed to be a case of neurofibroma.

Solitary Neurofibroma of the Soft Palate: A Rare Entity

The solitary neurofibroma is a benign tumor of neuronal origin uncommonly reported in the oral cavity. The possible association of this neoplasia with systemic pathologies, such as von Recklinghausen's disease and multiple endocrine neoplasia, makes its diagnosis fundamental. Solitary isolated neurofibroma of the soft palate not associated with von Recklinghausen's disease is an unusual tumor and probably only four cases have been reported in English literature previously. To the best of our knowledge, our case of soft palate neurofibroma in 17-year-old male represents the fifth reported in English literature, for which complete surgical excision was achieved with uneventful healing.

Sporadic Neurofibroma of the Tongue Unassociated with Neurofibromatosis Type I: A Clinicopathologic Study of Ten Cases

Neurofibromas rarely occur within the oral cavity and infrequently involve the tongue. The majority of lingual neurofibromas arise in patients affected by neurofibromatosis type 1 (NF1). Neurofibromas of the tongue unassociated with this disorder are exceedingly uncommon. The clinical and pathologic features of 10 cases of sporadic lingual neurofibromas, unassociated with NF1, were evaluated. The patients included six females and four males ranging in age from 30 to 69 years (mean 59 years; median 63 years). An asymptomatic or slowly enlarging lingual mass was the most common clinical presentation. None of the patients were documented to have NF1. Histologically, the tumors were unencapsulated and situated beneath an intact squamous mucosa. The tumors are comprised of spindle cells with wavy nuclei within a collagenous to myxoid stroma. One tumor was characterized by a plexiform growth pattern. The lesional cells were positive for S-100 protein. Clinical follow up, available for all patients, showed no recurrences and no subsequent development of additional clinical manifestations of NF1. Lingual neurofibromas should be distinguished from other peripheral nerve sheath tumors that can affect this anatomic site. This series of cases confirms that sporadic neurofibromas of the tongue may be rarely encountered in patients having no other features of NF1.

Removal of solitary neurofibroma of the external nose by intranasal approach

INTRODUCTION

Solitary neurofibroma originating from the external nose is extremely rare, and to our knowledge, only 3 cases have been reported so far in English literatures. It may originate from the ophthalmic (V1) and maxillary (V2) branches of the trigeminal nerve.

CASE REPORT

We present a rare case of solitary neurofibroma arising from the external nose, which was successfully removed by intranasal approach with intercartilaginous incision.

CONCLUSION

This case emphasizes two important points. First, we should keep in mind that this clinical entity is included in the differential diagnosis of soft tissue masses arising from the external nose. Second, we should choose the best surgical approach for complete removal with the maintenance of cosmetic appearance.

Unusual solitary neurofibroma on the lower lip of a child

Neurofibromas (NF) are benign tumors with involvement of the peripheral nerve, which is not frequently located in the oral cavity, and especially, extraordinary rarity on lower lip of a child. This report describes a case of a NF on lower lip in a 12-year-old Brazilian child. NF consists of a wide variety of cell types, including Schwann cells, perineurial cells, and fibroblasts. Due to cellular heterogeneity, several hypotheses have been proposed to explain the histogenesis of this lesion. One of them, it support an origin of Schwannian, while others emphasize the participation of both Schwann cells and perineural cells. Excisional biopsy was performed to establish definitive diagnosis. Microscopically, the lesion was composed of interlacing bundles of elongated cells with wavy nuclei and small nerve fibers. Immunohistopathologic assessment showed cells positive for S-100, confirming the diagnosis of NF. No recurrence was observed after 1-year follow-up. Pediatric dentists must have a thorough knowledge of this unusual lesion.

Imaging findings of benign peripheral nerve sheath tumor in jaw

OBJECTIVE

The aim of this study was to investigate the imaging characteristics of peripheral nerve sheath tumors (PNSTs) in the jaw.

STUDY DESIGN

Imaging studies of 6 patients were retrospectively reviewed. Conventional radiography, computed tomography, and magnetic resonance imaging were performed in all patients.

RESULTS

A fusiform lesion continuous with the nerve was observed in 2 cases, with the tumor arising within the inferior alveolar canal. In the other 4 cases, with the tumor arising outside the canal, the tumor had protruded and eroded into the bone. Protrusion was also present in 1 of the 2 cases, with the tumor arising within the canal. A target or fascicular sign was observed each in 1 case.

CONCLUSIONS

A fusiform lesion continuous with the nerve and a target or fascicular sign was only present in a few cases. The PNSTs, however, showed a tendency to protrude into the bone.

Solitary neurofibroma of the floor of the mouth: a case report

We present a case of a solitary neurofibroma of the floor of the mouth protruding into the submandibular region. A 51-year-old female presented with a 2-year history of swelling of the floor of the mouth. MRI revealed that the mass measuring 50 × 70 mm showed a homogenous, low signal intensity on a T1-weighted image and high signal intensity on a T2-weighted image. The tumor was completely removed through a cervical approach. Cases of a solitary neurofibroma originating from the floor of the mouth are extremely rare.

Solitary neurofibroma of the mandible: case report and review of the literature

A case is presented of a neurofibroma of the mandible without recurrence 6 years after surgery. Search for neurofibromatosis was negative. Eradication of the tumor was explained by the extent of the operation that was performed.

Benign neurogenic tumors of the oral cavity

Neurogenic tumors are rare in the oral cavity, particularly so when malignant. Traumatic neuroma, although usually included with neurogenic tumors, is a reactive process rather than a true neoplasm. Neurofibroma and schwannoma derive from nerve fibers, the perineurium, the endoneurium and the neurolemmomal cells. They present histological differences. The neurofibroma may present in solitary and generalized types; the latter also known as neurofibromatosis or von Recklinghausen's disease of the skin. We here report typical cases of benign neurogenic tumors of the oral cavity.

The pattern of distribution of laminin in neurogenic tumors, granular cell tumors, and nevi of the oral mucosa

Oral tumors of presumably neuroectodermal origin were stained with anti-laminin antibody by a double layered immunofluorescence technique. A marked positive staining for laminin was found in neurofibromas and neurilemmomas although the pattern of laminin distribution was slightly different. Accentuated staining was seen in Verocay bodies. In granular cell myoblastomas (GCM), small groups of tumor cells were encircled by laminin-positive material, whereas individual tumor cells were unstained. In nevi, diffusely spread nevus cells were surrounded by a rim of laminin, whereas when arranged in nests whole groups of cells were encircled by laminin as seen in the GCM. Ordinary oral fibromas included as controls were negative except for the expected positive staining of basement membranes normally occurring in the tissues. Immunohistochemical demonstration of laminin seems to be a valuable aid in differential diagnosis of soft tissue tumors and may provide useful information about the pathogenesis of various lesions.

Central neurilemmomas of the mandible. Report of a case

Central neurilemmomas involving the jaws are rare benign tumours probably originating from the neural sheath. We report 2 cases involving the posterior part of the mandible. The 1st case (male, age 20 years) had no symptoms of a tumour, which was discovered by accident in an orthopantomogram. The 2nd case (female, age 66 years) had experienced pain because of a tumour. The radiographic appearance of these tumours seemed to be non-specific. These 2 neurilemmomas have recurred, probably due to incomplete primary removal of the tumour.

Intraoral ancient neurilemoma (ancient schwannoma). Report of a case with histologic and electron microscopic studies

A case of ancient neurilemoma arising in the oral soft tissues is presented. Histologic and electron microscopic studies indicate that this tumor is, indeed, a variant of the neurilemoma and that the Schwann cell is the cell of origin. At the ultrastructural level, the bulk of the lesion is composed of numerous reduplications of basal lamina accompanying thin cytoplasmic processes and thus resembles a confluence of Verocay bodies as described in previous studies of classic neurilemomas. Heretofore unreported submicroscopic calcified spherules were observed scattered through the basal lamina material.

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.