Contenu connexe



  3. Epineurium Perineurium Endoneurium Fascicles Nerve fiber Node of Ranvier Schwann cell Myelin Axon From: Møller: Sensory Systems, 2003
  4. TRAUMATIC NEUROMA (Amputation neuroma) • Not a true neoplasm Attempt at repair of damaged nerve trunk i.e. hyperplasia of nerve fibers and their supporting tissues • Degeneration of the distal portion of the nerve after severance NF begins with swelling, fragmentation and disintegration of axis cylinder and myelin sheaths • Repair of damaged N begins with proliferation of neurilemmal sheaths and endoneurium
  5. P.Deb 7
  6. Wallerian degeneration The degenerative changes the distal segment of a peripheral nerve fiber (axon and myelin) undergoes when its continuity with its cell body is interrupted by a focal lesion. Syn: orthograde degeneration, secondary degeneration Interrupted axons regenerate from injury, provided that endoneural tube is intact
  7. • Repair - proliferation of axis cylinders, cells of the neurilemmal sheaths and endoneurium • Occurs unless proliferating proximal end meets some obstruction
  8. Clinical Features • Small nodule or swelling of mucosa • Central lesion • Slowly growing lesion • Middle aged adults, more in females • Pain locally
  9. • Irregular nodular proliferation along mental nerve
  10. Histologic Features • Mass of irregular interlacing neurofibrils and Schwann cells in connective tissue stroma • Proliferative nerve bundles occur as discrete bundles or spread diffusely • Mild chronic inflammatory cell infiltrate
  11. Hephazard arrangement of nerve bundles within fibrous CT stroma
  12. PALISADED ENCAPSULATED NEUROMA (Solitary circumscribed neuroma) • Benign neoplasm, not a form of traumatic neuroma • Trauma- etiology • Reactive lesion rather than a true neoplasm
  13. Clinical features • Striking predilection for face-90% • 5th-7th decade • Smooth, painless, dome shaped nodule, usually less than 1cm • Intraoral- common in hard palate, upper labial mucosa
  14. • Areas bordering mucocutaneous junctions, predominantly on face- nose, cheek, upper eyelid, lip and chin • Represent hyperplasia of nerve fibers, the axons and their nerve sheath cells.
  15. Histopathology • Well circumscribed, incomplete capsule • Some lesions- lobulated appearance • Interlacing fascicles of spindle shaped cells- consistent with Schwann cells (wavy, pointed) • Nuclei show parallel orientation within fascicles (more definite palisading and Verocay bodies typical of the Antoni type A tissue of neurilemmoma are not seen)
  16. • Solitary circumscribed neuroma- better descriptive term (tumor is not always encapsulated and usually not true palisaded) • Treatment- local surgical excision
  17. The Elephant Man Mistake • A popular movie ‘The Elephant Man’ portrayed the story of an individual (Joseph Merrick) with facial and scalp tissue proliferations as arising from an extreme case of Neurofibroma (NF). • Yet, the study of archived tissue from this man showed not NF but rather hyalinized C T (Proteus syndrome). • Individuals with NF have unnecessarily endured greater anxiety and a heavier psychologic burden since this Hollywood mistake.
  18. Neurofibroma (Neurofibromatosis, Von Recklinghausen’s Disease, fibroma molluscum, elephant man disease) • Benign tumor of nerve tissue origin • Arise from perineural fibroblasts • Seen either – As a solitary lesion – As a part of Neurofibromatosis- Autosomal dominant – Chromosome Type 1- 17q11.2 (Neurofibromin) – 22q12.1 (Schwannomin- type 2)
  19. Clinical Features- • Neurofibromatosis- Hereditary disease, no gender predilection, cosmetic problems, risk of malignant transformation • Oral Manifestations- – Discrete, non-ulcerated nodules of normal mucosal colour OR – Diffuse masses of tissue – Buccal mucosa, palate, alveolar ridge, tongue – Macroglossia due to diffuse involvement of tongue – Occasionally located centrally within jaw bones Neurofibroma
  20. • Slow-growing, soft, painless, small nodules to larger masses • Osseous changes, mental disorders, ocular diseases • Facial pain or paresthesia • Mandible- show fusiform enlargement of mand canal • Plexiform- variant- feels like “bag of worms”- pathognomonic for neurofibromatosis • Malignant transformation- MPNST……
  21. - Crowe’s sign
  22. Café-au-lait spots- • Neurofibromatosis- smooth borders (coast of california) • fibrous dysplasia (irregular- coastline of Maine) • Segmental neurofibromatosis- restricted to one location of the body
  23. NF II (acoustic form) • Chromosome 22 (Merlin) • Bilateral acoustic neuroma • CNS tumors • Cutaneous neurofibromas • Cafe-au-lait spots (less frequency)
  24. Histologic Features- • Solitary neurofibroma may or may not be well circumscribed • Interlacing bundles of spindle-shaped cells often with wavy nuclei • Cells are associated with delicate collagen bundles and variable amounts of myxoid matrix • Numerous mast cells • In plexiform neurofibroma- distorted masses of myxomatous peripheral nerve tissue still within perineural sheath; masses scattered within a collagen-rich matrix
  25. cells with wavy nuclei intermingled with neurites in irregular pattern Delicate interwining CT fibrils Cellular/ myxoid pattern Mast cells
  26. Treatment- • Solitary neurofibroma- surgical excision • For neurofibromas associated with Neurofibromatosis- surgical removal only for functional or cosmetic purpose Neurofibroma
  27. NEUROLEMMOMA Neurilemoma, perineural fibroblastoma, Schwannoma, neurinoma, lemmoma • Benign neural neoplasm of Schwann cell origin • Neurites are not a component of tumor as in neurofibroma • Composed of Schwann cells in poorly collagenized stroma • Proliferation of Schwann cells at one point inside perineurium
  28. Clinical Features • Slowly growing lesion • Any age • No gender predilection • Usually painless • Presence of tumor mass
  29. Oral Manifestations • Tongue, palate, floor of mouth, buccal mucosa, gingiva, lip, vestibule • Maxillary sinus and salivary glands, as well as retropharyngeal, nasopharyngeal and retrotonsillar areas • Mandible, bone destruction, expansion • Pain, paresthesia
  30. Histologic Features • Encapsulated • Antoni type A and Antoni type B • Antoni type A cells with elongated or spindle shaped nuclei aligned to form palisading pattern • Antoni type B does not exhibit palisading, but rather disorderly arrangement • Verocay bodies, small hyaline structures (consists of reduplicated BM & cytoplasmic processes) • Large irregularly shaped vessels which are characteristic of Schwannomas
  31. • Neurilemmoma may undergo degenerative changes (rare- in intraoral lesions). • When the changes are pronounced, the tumors have been called ancient Schwannomas (cyst formation, hyalinization, calcification, hemorrhage, and nuclear atypism).
  32. Schwannoma with extensive degenerative changes like hemorrhage, cyst formation & calcification
  33. Schwannoma of Submandibular Gland
  35. MULTIPLE ENDOCRINE NEOPLASIA SYNDROME (MEN SYNDROME-MEN III, MEN IIb) • Tumors or hyperplasias of neuroendocrine tissues • Autosomal dominant trait • Adrenal pheochromocytomas, medullary thyroid carcinoma, submucosal neuroma
  36. • Tall, lanky, marfanoid body type • Adrenal and thyroid tumors do not present until after puberty • oral mucosal neuromas - develop during 1st decade • Mutations of RET proto-oncogene – regulator of neural crest development and receptor of glial derived neurotrophic factor (GDNF)
  37. Clinical Features • 2-7 mm yellowish-white, sessile, painless nodule of lips, anterior tongue and buccal commissures • ‘Bumpy lip' • Similar lesion on eyelid, producing eversion of lid, & on the sclera • Facial skin, around nose, may be involved • Serum and urinary calcitonin levels elevated • Increase in serum levels of vanillylmandelic acid (VMA) • Altered epinephrine norepinephrine ratio
  38. • Luxol fast blue • S 100 • Col IV • Vimentin • NSE
  39. Histologic Features • Partially encapsulated aggregation or proliferation of nerves • Background of loose endoneurium-like fibrous stroma • Occasional hyperplasias and bulbous expansions
  40. Self limiting disease
  41. MELANOTIC NEUROECTODERMAL TUMOR OF INFANCY Pigmented ameloblastoma Melanoameloblastoma Retinal anlage tumor Melanotic progonoma Melanotic epithelial odontoma Pigmented teratoma
  42. • Uncommon osteolyticpigmented neoplasm • Origin- Odontogenic apparatus, pigmented anlage of the retina, sensory neuroectodermal tissues
  43. Clinical Features • Within first year of life • Male-to-female ratio of 6:7 • Anterior part of maxillary ridge • Skull, mandible, epididymis, brain • Rare lesions have been reported in shoulder, skin, femur, mediastinum, uterus
  44. • Rapidly growing, nonulcerated, darkly pigmented lesions • Displace or destroy developing deciduous and permanent dentition • Can present as unilocular, or rarely as multiloculated radiolucency • Increase in urinary level of VMA
  45. Histologic Features • Distinct biphasic pattern • Cells arranged in alveolus-like spaces lined by cuboidal or large polygonal cells, which have pale abundant cytoplasm may contain melanin pigment • Central portions small round neuroblast like cells which show little cytoplasm, exhibit round, deeply staining nucleus
  46. Treatment - Partial maxillectomy Local recurrence
  47. • Masson’s fontana • HMB 45 • NSE /Synaptophysin
  48. MALIGNANT PERIPHERAL NERVE SHEATH TUMOR Malignant Schwannoma, malignant neurilemoma, neurogenic sarcoma, neurofibrosarcoma
  49. • MPNST- is preferred name for spindle cell malignancy of peripheral nerve Schwann cells • Mostly trigeminal nerve involved.
  50. Neurofibrosarcoma
  51. • 20-50 years people are affected. • Males • Persons with NFI typically occur a decade earlier • most common head and neck area of involvement is neck, but oral cavity- extremely rare • Mostly in tongue, soft palate, mandible. • Pain, paresthesia present. • Half cases-neurofibromatosis (4% of neurofibromatosis patients)
  52. Roentgenographic Features • Diffuse radiolucency -INFILTRATIVE • Smooth radiolucency
  53. H/P • SPINDLE CELLS –wavy or comma-shaped outline. • Arranged in sweeping fascicles pattern. • Highly pleomorphic cells and mitotic activity • EPITHELOID, MESENCHYMAL/GLANDULAR • TRITON TUMOR- rhabdomyoblastic differentiation • Treatment- wide surgical excision
  54. Epithelioid • Plump, rounded or ovoid epithelioid cells scattered in small numbers & in well defined clusters • Vesicular or hyperchromatic nuclei • Rhabdomyoblastic differentiation - Triton tumor Glandular • Well-differentiated ductal structures lined by simple, stratified, cuboidal or columnar epithelial cells with occasional goblet cells • The lumina contain PAS-positive, diastase-resistant mucus • Multiple sarcomatous tissue types
  55. OLFACTORY NEUROBLASTOMA Esthesioneuroblastoma, esthesioneuroepithelioma • Most frequently in nasal cavity and nasopharynx • Ethmoidal sinus, • In or invading maxillary sinus • Neuroectodermal in origin arising from basal cells of the olfactory epithelium
  56. Clinical Features • Painful swelling in area of nasal fossa- nasal obstruction, epistaxis • Anosmia, pain • Invasive, destructive tumor, but only rarely metastasizes
  57. Kadish clinical staging system • STAGE A- Tumour confined to the nasal cavity • STAGE B- Tumour involving one or more PNS • STAGE C- Tumour extending beyond nasal cavity & PNS • STAGE D- Tumour with lymph node or distant metastasis
  58. Histologic Features • Densely packed masses of small darkly staining cells with poorly defined eosinophilic cytoplasm regular round vesicular nucleus • Rosette, pseudorosette formation common • Eosinophilic neurofibrils extend into lumen from cell borders • Stroma has fibrillar neuroid pattern
  59. Rx- surgical excision+ radiotherapy, chemotherapy)
  60. • Rosettes
  61. Thank You