Year : 2005 | Volume
: 9 | Issue : 1 | Page : 27--29
An unusual presentation of a case of schwannoma
Cyril Pandarakalam, S Sudha, PM Shameena, V Ipe Varghese
Department of Oral and Maxillo Facial Pathology , Govt. Dental College, Calicut, Kerala, India
V Ipe Varghese
Department of Oral and Maxilla Facial Pathology, Govt. Dental College, Calicut, Kerala
Neural tumours are a rare entity in the oral cavity. Here, we report a case of neurilemmoma, which has manifested as a gingival swelling and its clinical and histopathological features and management are discussed
|How to cite this article:|
Pandarakalam C, Sudha S, Shameena P M, Varghese V I. An unusual presentation of a case of schwannoma.J Oral Maxillofac Pathol 2005;9:27-29
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Pandarakalam C, Sudha S, Shameena P M, Varghese V I. An unusual presentation of a case of schwannoma. J Oral Maxillofac Pathol [serial online] 2005 [cited 2021 May 17 ];9:27-29
Available from: https://www.jomfp.in/text.asp?2005/9/1/27/39057
Neurilemmoma (schwannoma) is a benign, encapsulated perineural tumor of neuroectodermal derivation that originates from the Schwann cells of the neural sheath of motor and sensitive peripheral nerves. The etiology is still unknown  . In 1910, Verokay first described a group of neurogenic tumours; he referred them to as 'neurinomas'. In 1935, it was proposed that these tumours arose from nerve sheath elements and they were termed 'neurilemmomas'  . Of the large variety of terms under which these tumours have been reported in the past, only three are still in current use: neurinoma, neurilemoma (neurilemmoma), and schwannoma. Both electron microscopy and immunohistochemistry have established that these tumours are composed of Sehwann cells  .
Schwannomas may arise from cranial and spinal nerve roots or from peripheral nerves. Schwannomas have a predilection for sensory nerves  .The vast majority of intracranial schwannomas arise from the eighth cranial nerve  . Of the motor nerve, facial is most frequently involved. Spinal tumours arise predominantly from posterior roots  . The lesion does occur with some frequency in patients with neurofibromatosis  .
On occasions, the tumour can arise centrally within the bone and may produce bony expansion. Intraosseous examples are most common in posterior mandible and usually appear as unilocular or multilocular radiolucencies on radiographs  . lntramandibular turnours arise from mandibular nerve  .
A case of neurilemmoma of the gingiva in a 25-year-old male is described. This case has been reported for its rarity. The histological characteristics are discussed.
A 25-year old man presented with an otherwise asymptomatic slow growing gingival swelling in relation to the buccal aspect of 23, 24, and 25 of 9 years duration. [Figure 1]. Clinical diagnosis was fibomatosis gingivae. Examination revealed a smooth, firm, non-tender, swelling of 3 x 2 sq. cm in size. There was no cervical or submental lymph node enlargement. The haemotological and biochemical parameters were within normal limits. Incision biopsy was taken and subjected to histopathological examination.
Haematoxylin and Eosin stained sections showed cellular regions with predominately benign spindle cells in many intersecting bundles (Antoni type A tissue) [Figure 2], palisading around eosinophilic regions called Verocay bodies [Figure 3]. Other areas showed a disorderly arrangement of cells and fibers with areas of what appeared to be edema fluid and with rnicrocyst formation (Antoni type B tissue) [Figure 4]. Mitotic figures were absent. Based on these findings a histopathological diagnosis of schwannoma was made.
Schwannomas form firm, well-circumscribed, encapsulated round, or ovoid tumors  . The tumor is usually solitary, smooth-surfaced, slow growing, and generally asymptomatic  , although tenderness or pain may occur in sonic instances. It may resemble any of a number of benign oral soil-tissue lesions. The central lesion in bone may produce considerable destruction of bone with expansion of the cortical plates and thus resemble a more serious lesion  . Pain and parasthesia are not uncommon for intrabony tumours  .
The lesion may develop at any age arid it is most common in young and middle aged adults and can range from a few millimeters to several centimeters in size  . There is no gender predilection. Head and neck arc one of the most frequent locations, but intraoral development is quite uncommon. Intra orally, soft tissue neurilemmoma most frequently affects tongue, palate, and buccal mucosa. Lip and gingiva are most frequently affected  . Schwannoma accounts for just over 1 % of benign tumors reported in the oral cavity  . Although it originates from the nervous tissue, only in 50% of the cases, a direct relation with a nerve is demonstrated  . Immunohistochemically, schwannomas express S-100 protein, Vimentin, Leu-7 antigen, and glial fibrillary acidic proteins (GFAP)  .
Laboratory studies generally are not beneficial. Plain radiograph findings generally are not specific. Special studies to consider are CT scan or MRI. MRI is particularly useful. Biopsy may be needed to clearly define the tissue type. For hone lesions and for particularly large soft tissue lesions, biopsy is prudent to ensure correct diagnosis and management 
Differential diagnosis include fibroma, neurofibroma, neurosarcoma, ganglion cyst, giant cell tumor of tendon sheath, or lipoma  .
There are variants of benign schwannomas such as plexiform or multinodular schwannoma, cellular schwannoma, Wagner-Meissner schwannoma, granular cell schwannoma, and nerve sheath myxoma-neurothecoma. In large tumours, the connective tissue stroma may be more abundant and consist of dense bands of hyalinised collagen disrupting the cellular pattern. This has been interpreted as a sign of aging ("ancient schwannomas"). Patchy calcification may also occur  .
The treatment of a benign solitary neurilemmoma is enucleation. Excision of a segment of a major peripheral nerve is contraindicated  . The lesion is excised marginally and the nerve fibers are spared. Recurrence is unlikely with complete resection. Patients usually have rapid and complete relief of pain, with excellent longterm results. Malignant change is extremely rare in isolated lesions  .
Schwannoma a rare entity in the oral cavity is presented here. The clinical Findings alone will not help in arriving at a diagnosis; biopsy is mandatory for all such swellings of oral cavity.
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