{"id":8116,"date":"2016-08-21T08:42:02","date_gmt":"2016-08-21T08:42:02","guid":{"rendered":"http:\/\/biomedpharmajournal.org\/?p=8116"},"modified":"2017-02-17T07:36:49","modified_gmt":"2017-02-17T07:36:49","slug":"neural-tumors-of-oral-and-maxillofacial-region","status":"publish","type":"post","link":"https:\/\/biomedpharmajournal.org\/staging\/vol9no2\/neural-tumors-of-oral-and-maxillofacial-region\/","title":{"rendered":"Neural Tumors of Oral and Maxillofacial Region"},"content":{"rendered":"

Introduction\u00a0<\/strong><\/p>\n

Nerve cells and supporting cells are the 2 main cells in the nervous system. Neuron or nerve cell is the main structural and functional unit of the system. Supporting cells of the CNS are neuralgia cells ,peripheral nervous system are schwann cells and satellite cells. Neural tumors are of neuroectodermal in origin. It appears as painless swelling which is of smooth surface in the soft tissues of the mouth. The most common site is being the tongue. In the head and neck region the most of the them are benign\u00a0 tumors<\/p>\n

Classification of neural tumors\u00a0<\/strong><\/p>\n

(WHO 1992 )<\/strong><\/p>\n

Benign Tumours<\/strong><\/p>\n

Traumatic Neuroma<\/p>\n

Perineural Fibrosis<\/p>\n

Neuromuscular HamartomaFibroblastoma, Neurinoma, Lemmoma<\/p>\n

Nerve Sheath Ganglion<\/p>\n

Schwannoma – plexiform , cellular , ancient or degenerated<\/p>\n

Neurofibroma and Neurofibromatosis or Vonrecklingausen\u2019 Disease Of Skin<\/p>\n

Diffuse Neurofibroma<\/p>\n

Pacinian Neurofibroma<\/p>\n

Epitheloid Neurofibroma<\/p>\n

Granular Cell Tumor<\/p>\n

Melanocytic Schwannoma: Pigmented Schwannoma<\/p>\n

Nerve Sheath Myxoma<\/p>\n

Ectopic Meningioma.<\/p>\n

Ganglioneuroma<\/p>\n

Pigmented Neuroectodermal Tumor of Infancy<\/p>\n

Malignant Tumours<\/strong><\/p>\n

Malignant peripheral nerve sheath tumors (MPNST).<\/p>\n

Malignant Schwannoma<\/p>\n

Neurofibrosarcoma<\/p>\n

Malignant peripheral nerve sheath tumor with Rabhdomyosarcoma , glandular differentiation and Epitheloid<\/p>\n

Malignant granular cell tumor<\/p>\n

cellular cell sarcomas: Malignant melanoma of soft parts<\/p>\n

Malignant melanocytic Schwannoma.<\/p>\n

Neuroblastoma<\/p>\n

Ganglioneuroblastoma<\/p>\n

Neuropithelioma<\/p>\n

Traumatic neuroma\u00a0<\/strong><\/p>\n

It occurs due to the trauma during\u00a0 extraction of tooth , any physical injuries or at the site of previous injuries1<\/sup>. Clinically \u00a0it appears as a swelling or small nodule near the mental foramen, lips or tongue. Traumatic neuroma of the mental foramen was first reported by cahn2<\/sup>. Bone associated with nerve trunk may also occur. It is slow growing and becomes larger in size.<\/p>\n

Histopathological appearance of traumatic neuroma of irregular mass with interlacing neurofibrils and schwann cells. Connective tissue is scanty and it is derived from perineurium. Proliferating nerve fibers may occur diffusely throughout the lesion or small discrete islands.3<\/sup><\/p>\n

Special stains used to identify collagen are the trichrome methods ( masson , Mallory)4<\/sup>. In IHC staining methods S100 and EMA appears to be positive for perineural components<\/p>\n

Palisaded encapsulated neuroma\u00a0<\/strong><\/p>\n

It is benign true neoplasm. It cause primary hyperplasia of nerve fibers , axons and their sheath cells.5 <\/sup>clinically appears as a solitary , cutaneous tumor occurring mainly mucocutaneous junctions on the face. Oral cavity is rarest site of origin. Histopathological\u00a0\u00a0 appearance of neuroma shows encapsulated mass which may be complete or incomplete. Tumor consist of interlacing fascicles of spindle cells with moderately cellular and some have lobulated appearance. Special stains like schofield methos reveals the presence of numerous axons in the tumor. Differential diagnosis of the lesion is neurofibroma and neurilemoma5,6<\/sup>.<\/p>\n

Schwannoma (neurilemoma , perineural fibroblastoma\u00a0 ) \u00a0<\/strong><\/p>\n

It is a benign\u00a0 neural neoplasm of nerve sheath origin. Schwann cells forms the inner layer of the peripheral nerve sheath. Head and neck region are most commonly affected. Bilateral or multiple\u00a0 lesions is a feature of neurofibromatosis which is a hereditary condition5<\/sup>. Clinically it appears as solitary ,slow growing and pain may be associated in some lesions. In the head and neck region tumors occurs on both oral and paraoral region , in which tongue being the most commonly affected site3,5<\/sup>. Intraosseous or central lesion affects both the maxilla and mandible. Pain , bone destruction and expansion of cortical plates may be seen in some of the lesions. The tumor is composed of 2 types of tissues Antoni A and Antoni B. Histopathological appearance of Antoni A shows spindle shaped cells with palisading arrangement and fibers are arranged in whorls or swirls. Verocay bodies are striking feature of the lesion. Antoni b does not exhibit a palisading arrangement and spindle cells are disorderly arranged. Microcyst formation is seen7<\/sup>. One of the histological variant of schwannoma is the ancient schwannoma (hemosiderin and hemorrahgic areas can be seen ) 8<\/sup>. Schwannoma cells are positive for S 100 protein and not for EMA<\/p>\n

Neurofibroma\u00a0<\/strong><\/p>\n

It arises from both the schwann cells and perineural fibroblasts. Two forms of neurofibroma are solitary neurofibroma and neuro fibromatosis<\/p>\n

Solitary neurofibroma\u00a0<\/strong><\/p>\n

It is a non encapsulated tumor of slow growing consisting of schwann cells and perineural cells. Neurofibroma is awell\u00a0 demarcated lesion with proliferation of interlacing bundles of spindle cells ,wavy nuclei and sometimes melanocytes can be seen. Mast cells are the characteristic feature of the lesion which helps in diagnosis3<\/sup>. Solitary plexiform neurofibroma is a variant of neurofibroma which may be associated with neurofibromatosis and had a risk of malignant transformation3<\/sup>.<\/p>\n

Neurofibromatosis (Von Recklinghausen\u2019s Disease of Skin)\u00a0<\/strong><\/p>\n

it is a autosomal dominant condition with multiple neurofibromas , skin pigmentation and bony abnormalities which may transform into neurofibrosarcoma 5<\/sup>. Two types of neurofibromatosis are defined : NF type 1 \u2013 mutations on gene neurofibromin and NF type 2 \u2013 mutations on gene schwannomin. Clinical appearance shows caf\u00e9 au`lait macules, Axillary freckling (Crowe sign), Iris freckling (Lisch spots) and \u00a0Bony changes\u00a0 are also seen9<\/sup>.<\/p>\n

\u00a0<\/strong>Malignant peripheral nerve sheath tumor ( neurogenic sarcoma , neurofibrosarcoma )\u00a0<\/strong><\/p>\n

It arises from peripheral nerve schwann cells and its rare in the oral cavity. Sarcomas are of 2 types 1. Malignant transformation of neurofibromatosis to sarcoma10<\/sup> 2. Malignancy in the absence of neurofibromatosis 11<\/sup>. Malignant schwannoma commonly seen in lips, buccal mucosa and palate where as in central tumors mandible is more common. Histopathological appearance shows spindle shaped cells with comma shaped nuclei and cellular , nuclear pleomorphism , mitotic figures are very high. Schwannoma appears in 3 forms of pattern\u00a0 1. Epitheloid 2. Rhabdomyoblastic differentiation 3. Glandular or mesenchymal 3<\/sup>.<\/p>\n

Conclusion\u00a0<\/strong><\/p>\n

There is a chance of malignant transformation in benign tumors is seen so it is important to distinguish between the benign neoplasms and peripheral nerve neoplasms<\/p>\n

References\u00a0<\/strong><\/p>\n

    \n
  1. HUB E. Amputation neuromas: Their development and prevention. Archives of Surgery<\/li>\n
  2. Cahn LR. Traumatic (amputation) neuroma. American Journal of Orthodontics and Oral Surgery 1939;25(2):190-3.1920; 1(1):85.<\/li>\n
  3. Rajendran R, Sivapada Sundaram B. Benign and malignant tumors of the oral cavity. Shafer, Hine, Lavy, editors Shafer’s Text book of Oral Pathology India: Elsevier2009:120-7.<\/li>\n
  4. Sist TC. Traumatic neuroma of the oral cavity:: Report of thirty-one new cases and review of the literature. Oral Surgery, Oral Medicine, Oral Pathology 1981;51(4):394-402.<\/li>\n
  5. Neville.B, Damm.D, Allen.C, Bouquot.J. Soft tissue tumors: Chapter12. 3ed. Delhi: Elsevier; 2009.<\/li>\n
  6. Dover.J,From.L,Lewis.A.Palisaded encapsulated neuromas: a clinicopathologic study. Archives of Dermatology 1989 ;125(3):386-9.<\/li>\n
  7. Chen SY, Miller AS. Neurofibroma and schwannoma of the oral cavity: A clinical and ultrastructural study. Oral Surgery, Oral Medicine, Oral Pathology1979;47(6):522-8.<\/li>\n
  8. McCoy JM, Mincer HH, Turner JE. Intraoral ancient neurilemoma (ancient schwannoma):: Report of a case with histologic and electron microscopic studies. Oral Surgery, Oral Medicine, Oral Pathology1983;56(2):174-84.<\/li>\n
  9. Ellis GL, Abrams AM, Melrose RJ. Intraosseous benign neural sheath neoplasms of the jaws: Report of seven new cases and review of the literature. Oral Surgery, Oral Medicine, Oral Pathology 1977;44(5):731-43.<\/li>\n
  10. Harkin JC, Reed RJ. Tumors of the peripheral nervous system. 1969.<\/li>\n
  11. Sordillo PP, Helson L, Hajdu SI, Magill GB, Kosloff C, Golbey RB, Beattie EJ. Malignant schwannoma clinical characteristics, survival, and response to therapy. Cancer 1981; 47 (10) : 2503-9.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

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