This document provides information on various tumors that can affect nerves and muscles in the oral cavity. It summarizes different types of benign and malignant nerve tumors, including traumatic neuromas, palisaded encapsulated neuromas, neurofibromas, neurilemmomas (schwannomas), malignant peripheral nerve sheath tumors, and others. For each tumor type, it describes clinical features, histologic characteristics, associated syndromes, treatment approaches, and other relevant details.

1. TUMOR OF NERVES AND MUSCLES
DR. SUHASINI GP
SENIOR LECTURER
DEPT. ORAL &MAXILLOFACIAL PATHOLOGY AND MICROBIOLOGY
SUBHARTI DENTAL COLLEGE AND HOSPITAL
SWAMI VIVEKANAND SUBHARTI UNIVERSITY
MEERUT. UP
Subject: Oral Pathology

2. TUMOR OF NERVES

4. Epineurium
Perineurium
Endoneurium
Fascicles
Nerve fiber
Node of Ranvier
Schwann cell
Myelin
Axon
From: Møller: Sensory Systems, 2003

6. 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

7. P.Deb 7

10. 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

11. • Repair - proliferation of axis cylinders, cells of
the neurilemmal sheaths and endoneurium
• Occurs unless proliferating proximal end
meets some obstruction

12. Clinical Features
• Small nodule or swelling of mucosa
• Central lesion
• Slowly growing lesion
• Middle aged adults, more in females
• Pain locally

14. • Irregular nodular proliferation along mental nerve

15. 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

16. Hephazard arrangement of nerve bundles within fibrous CT stroma

17. PALISADED ENCAPSULATED NEUROMA
(Solitary circumscribed neuroma)
• Benign neoplasm, not a form of traumatic
neuroma
• Trauma- etiology
• Reactive lesion rather than a true neoplasm

18. 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

19. • 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.

22. 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)

25. • Solitary circumscribed neuroma- better
descriptive term
(tumor is not always encapsulated and usually
not true palisaded)
• Treatment- local surgical excision

27. 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.

29. 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)

30. 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

31. • 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……

32. - Crowe’s sign

34. 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

37. NF II (acoustic form)
• Chromosome 22 (Merlin)
• Bilateral acoustic neuroma
• CNS tumors
• Cutaneous neurofibromas
• Cafe-au-lait spots (less frequency)

38. 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

39. cells with wavy nuclei
intermingled with
neurites in irregular
pattern
Delicate interwining CT
fibrils
Cellular/ myxoid
pattern
Mast cells

40. Treatment-
• Solitary neurofibroma- surgical excision
• For neurofibromas associated with
Neurofibromatosis- surgical removal only for
functional or cosmetic purpose
Neurofibroma

41. 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

45. Clinical Features
• Slowly growing lesion
• Any age
• No gender predilection
• Usually painless
• Presence of tumor mass

46. 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

49. 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

52. • 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).

53. Schwannoma with extensive degenerative
changes like hemorrhage, cyst formation & calcification

54. Schwannoma of Submandibular Gland

55. MULTIPLE ENDOCRINE NEOPLASIA SYNDROME

56. 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

57. • 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)

58. 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

59. • Luxol fast blue
• S 100
• Col IV
• Vimentin
• NSE

63. Histologic Features
• Partially encapsulated aggregation or proliferation
of nerves
• Background of loose endoneurium-like fibrous
stroma
• Occasional hyperplasias and bulbous expansions

64. Self limiting disease

65. MELANOTIC NEUROECTODERMAL TUMOR OF INFANCY
Pigmented ameloblastoma
Melanoameloblastoma
Retinal anlage tumor
Melanotic progonoma
Melanotic epithelial odontoma
Pigmented teratoma

66. • Uncommon osteolyticpigmented neoplasm
• Origin- Odontogenic apparatus, pigmented
anlage of the retina, sensory neuroectodermal
tissues

67. 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

69. • 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

71. 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

72. Treatment - Partial maxillectomy
Local recurrence

73. • Masson’s fontana
• HMB 45
• NSE /Synaptophysin

75. MALIGNANT PERIPHERAL NERVE SHEATH TUMOR
Malignant Schwannoma, malignant
neurilemoma, neurogenic sarcoma,
neurofibrosarcoma

76. • MPNST- is preferred name for spindle cell
malignancy of peripheral nerve Schwann cells
• Mostly trigeminal nerve involved.

77. Neurofibrosarcoma

78. • 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)

80. Roentgenographic Features
• Diffuse radiolucency -INFILTRATIVE
• Smooth radiolucency

81. 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

83. 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

86. 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

87. Clinical Features
• Painful swelling in area of nasal fossa-
nasal obstruction, epistaxis
• Anosmia, pain
• Invasive, destructive tumor, but only
rarely metastasizes

88. 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

90. 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

91. Rx- surgical excision+ radiotherapy, chemotherapy)

92. • Rosettes

95. Thank You