Benign odontogenic and non odontogenic tumours

1. 1

2. Benign Odontogenic
and Non-Odontogenic
Tumors of the Jaws
ABHISHEK ROY
III MDS
2

3. Classification of Benign Odontogenic
Tumors
 I. Odontogenic epithelium without odontogenic
ectomesenchyme
 A. Ameloblastoma
 B. Calcifying epithelial odontogenic tumor
 C. Adenomatoid odontogenic tumor
 II. Odontogenic epithelium with odontogenic
ectomesenchyme with or without hard tissue formation
 A. Ameloblastic fibroma
 B. Ameloblastic fibro-odontoma
 C. Compound odontoma
 D. Complex odontoma
 III. Odontogenic ectomesenchyme with or without included
odontogenic epithelium
 A. Odontogenic fibroma
 B. Odontogenic myxoma
 C. Cementoblastoma
3

4. WHO Classification, 2017
Epithelial Origin –
Ameloblastoma
Calcifying epithelial odontogenic tumour
Adenomatoid odontogenic tumour
Mixed Origin –
Ameloblastic Fibroma
Odontoma
Mesenchymal Origin –
Odontogenic Myxoma
Cementoblastoma
Cemento-ossifying fibroma
4

5. Tumors of Odontogenic
Epithelium
5

6. Ameloblastoma
 The ameloblastoma is the most common
clinically significant odontogenic tumor.
 It may develop from
 Cell rests of the dental lamina
 Developing enamel organ
 Epithelial lining of odontogenic cyst
 Basal cells of oral mucosa
6

7. Ameloblastoma
 It is typically slow-
growing, locally invasive
and runs a benign course
 H.G.B. Robinson
described it as being a
benign tumor that is
“usually unicentric, non-
functional, intermittent
in growth, anatomically
benign and clinically
persistent”
7

8. Ameloblastoma
 Ameloblastomas occur in 3 different
clinico-radiographic situations requiring
different therapeutic considerations and
having different prognoses.
 Conventional Solid/Multicystic (86 % of all
cases)
 Unicystic (13 % of all cases)
 Peripheral or Extraosseous (1 % of all cases)
8

9. Multicystic
Ameloblastoma
9

10. Solid or Multicystic Ameloblastoma:
Clinical Features
 Patient Age: Approximately equal
frequency from the third through the
seventh decades
 Sex Predilection: Approximately equal
 Gender Predilection: Approximately equal
10

11. 11

12. Solid or Multicystic
Ameloblastoma:
Radiographic Features
Radiolucent lesion which
is usually well-
circumscribed; it may be
unilocular or
multilocular (soap-
bubble, honeycomb);
occasionally an
ameloblastoma will be
ill-defined with a ragged
border
12

13. Solid or Multicystic Ameloblastoma:
Histologic Features
 There are six microscopic subtypes –
 Follicular
 Plexiform
 Acanthomatous
 Granular
 Basal
 Desmoplastic
13

14. Solid or Multicystic
Ameloblastoma: Histologic
Features
The follicular type is composed of islands of epithelium which resemble
the enamel organ in a mature fibrous connective tissue stoma.
14

15. Solid or Multicystic Ameloblastoma:
Histologic Features
The plexiform type is composed of long, anastomosing cords or larger
sheets of odontogenic epithelium. Its stroma tends to be loose and
more vascular.
15

16. Solid or Multicystic Ameloblastoma:
Histologic Features
The acanthomatous type shows evidence of extensive squamous
metaplasia with keratin formation in the island of odontogenic
epithelium.
16

17. Solid or Multicystic Ameloblastoma:
Histologic Features
In the granular cell type there is transformation of groups of epithelial
cells to granular cells; the nature of the granular change is unknown.
This type is more common in young patients and has been shown to be
clinically aggressive.
17

18. Solid or Multicystic ameloblastoma:
Histologic Features
The basaloid type is the least common and is composed of uniform
basaloid cells with no stellate reticulum.
18

19. Solid or Multicystic Ameloblastoma:
Histologic Features
The desmoplastic form is composed of islands/cords of odontogenic
epithelium in a very dense collagenous stroma.
19

20. Solid or Multicystic Ameloblastoma:
Treatment
 Treatments have ranged from simple
enucleation and curettage to en bloc
resection.
 Marginal resection is the most widely used
method of treatment with the least
recurrences reported (up to 15 %).
 Most surgeons advocate a margin of at least
1.0 cm beyond the radiographic limits of the
tumor as the tumor often extends beyond
the apparent radiologic/clinical margins.
20

21. Solid or Multicystic Ameloblastoma:
Treatment
 Treatment with curettage has resulted in
recurrence rates ranging from 55-90 %.
 Ameloblastomas of this type arising in the
maxilla are particularly dangerous as it is
often difficult in getting adequate
margins.
 Rarely is an ameloblastoma life
threatening.
21

22. 22

23. 23

24. 24

25. Unicystic
Ameloblastoma
25

26. Unicystic Ameloblastoma:
Clinical Features
 Patient Age: 50% that have been reported
were during the second decade of life
 Sex Predilection: Approximately Equal
 Location: 90 % occur in the mandible usually
in the posterior region.
26

27. 27

28. Unicystic Ameloblastoma:
Radiographic Features
Typically appears as a radiolucency
around the crown of an unerupted
tooth (most commonly a mandibular
third molar)
28

29. 29

30. Unicystic Ameloblastoma: Histologic
Features
 Luminal: the tumor is
confined to the luminal
surface of the cyst.
 Intraluminal/plexiform: the
tumor projects from the
cystic lining; sometimes
resembles the plexiform type
of solid/multicystic
ameloblastoma.
 Mural: the tumor infiltrates
the fibrous cystic wall
30

31. Unicystic Ameloblastoma: Treatment
and Prognosis
 Enucleation of the cyst is probably adequate
for the luminal and intraluminal/plexiform
types
 Treatment of the mural type is controversial
with some surgeons believing that local
resection is best
 10-20 % recurrence after enucleation and
curettage with all unicystic ameloblastomas
31

32. Peripheral
Ameloblastoma
32

33. Peripheral Ameloblastoma
 These tumors are extraosseous and
therefore occupy the lamina propria
underneath the surface epithelium but
outside of the bone.
 Histologically, these lesions have the same
features as the intraosseous forms of the
tumor
33

34. Peripheral Ameloblastoma: Clinical
Features
 Patient Age: Wide age range but most
occur during middle-age
 Gender Predilection: Uncertain
 Location: There is a slight predilection for
the mandible. The buccal mucosa has
been the site in a few reported cases
34

35. Peripheral Ameloblastoma:
Histologic Features
Histologic Appearance: Islands of ameloblastic epithelium are observed
in the lamina propria; plexiform and follicular patterns are the most
common; in 50 % of the cases the tumor connects with the basal cell
layer of the surface epithelium
35

36. Peripheral Ameloblastoma:
Treatment and Prognosis
 Patients respond well to local surgical
excision
 Some reports indicate a 15 % recurrence rate
but in these cases as second surgical
procedure results in cure
36

37. Calcifying Epithelial
Odontogenic Tumour
PINDBORG TUMOUR
37

38. Calcifying Epithelial Odontogenic
Tumor (CEOT; Pindborg Tumor)
 Pindborg tumor accounts for < 1 % of all
odontogenic tumors
 Bony lesions most commonly present as
painless, slow-growing swellings
 It is clearly of odontogenic origin but its
histogenesis is uncertain
 The tumor cells are said to resemble cells
of the stratum intermedium
38

39. CEOT: Clinical Features
 Patient Age: Patients ages range from the
2nd to the 10th decades with a mean
around 40 years
 Gender Predilection: None
 Location: 75 % of the CEOTs occur in the
mandible with most occurring in the
posterior region
39

40. 40

41. CEOT: Radiographic Features
 CEOTs occur as radiolucent lesions
with/without opaque foci
 They are usually well-circumscribed and
may be unilocular or multilocular
 Slightly over 50 % of the CEOTs are
associated with an impacted tooth
41

42. 42

43. 43

44. CEOT: Histologic Features
 This lesion is typically composed
of islands, sheets or strands of
polyhedral epithelial cells in a
fibrous stroma.
 Areas of amorphous, eosinophilic,
hyalinized extracellular material
may be scattered throughout.
 Cells outlines are distinct and
intercellular bridges may be seen.
 Nuclei show considerable
variation with giant nuclei and
pleomorphism observed.
 Calcifications may be noted as
well as amyloid-like material.
Liesegang rings also may be
present.
44

45. CEOT: Additional Features, Treatment
and Prognosis
 Conservative local resection is the treatment of
choice as these lesions are typically less
aggressive than the ameloblastoma.
 With this treatment the recurrence rate is
approximately 15 % and the overall prognosis is
good
 However, larger lesions (>4cm) require marginal
resection
45

46. Misra SR, Lenka S, Sahoo SR, Mishra S. Giant Pindborg Tumor (Calcifying Epithelial Odontogenic Tumor):
An Unusual Case Report with Radiologic-Pathologic Correlation. J Clin Imaging Sci 2013;3:S11
46

47. Adenomatoid
Odontogenic
Tumour
47

48. Adenomatoid Odontogenic Tumor
(AOT)
 Formerly called an adenoameloblastoma,
the AOT represents about 3-7 % of all
odontogenic tumors.
 This epithelial tumor has an inductive
effect on the odontogenic
ectomesenchyme with dentinoid
frequently being produced.
48

49. AOT: Clinical Features
 Patient Age: The peak age is in the second
decade with a mean around 17 years
 Gender Predilection: Females, 2:1
 Location: 65% of the AOTs occur in the
maxilla with most occurring in the canine
region. 75% percent of the cases are
associated with the crown of an
unerupted tooth
49

50. 50

51. AOT: Radiographic Features
 AOTs typically appear as
pericoronal radiolucencies,
which may have radiopaque
material (“snowflake”
calcifications) within the
lucency.
 These lesions are frequently
asymptomatic and therefore
are discovered upon routine
radiographic examination.
51

52. 52

53. AOT: Histologic Features
 The lesion is usually
surrounded by a thick, fibrous
capsule.
 The tumor is composed of
spindle-shaped epithelial cells
that form sheets, strands or
whorled masses with little
connective tissue.
 The epithelial cells may form
rosette-like structures, tubular
or duct-like structures may be
prominent or absent.
 Calcifications may be
observed in the tumor mass.
53

54. AOT: Treatment and Prognosis
 Enucleation is the treatment of choice as
the tumor is easily removed from the
bone.
 AOTs seldom recur
54

55. Ameloblastic
Fibroma
55

56. Ameloblastic Fibroma: Clinical
Features
 This true mixed odontogenic tumor is
more common in patients in the 1st and
2nd decades of life with a mean of 14
years.
 It is slightly more common in males than
females
 Approximately 70 % of the ameloblastic
fibromas occur in the posterior mandible
56

57. 57

58. 58

59. Ameloblastic Fibroma: Radiographic
Features
 Generally, these lesions
appear as either a
unilocular or multilocular
radiolucency.
 They tend to be well-
defined and may have a
sclerotic border.
 Approximately, 50 % are
associated with an
unerupted tooth.
59

60. Ameloblastic Fibroma: Histologic
Features
 The tumor is composed of a cell-rich mesenchymal
tissue resembling the primitive dental papilla
admixed with proliferating odontogenic epithelium.
60

61. Ameloblastic Fibroma: Additional
Features, Treatment and Prognosis
 The tumor is often encapsulated with small
tumors usually being asymptomatic. Larger
tumors produce swelling, which can expand
the cortex and be quite pronounced.
 Most ameloblastic fibromas are treated by
conservative surgical excision; however, a
20% recurrence rate has led some surgeons
to recommend a more aggressive approach
in case of larger lesions
61

62. Odontoma
62

63. Odontoma
 The odontoma is the most common odontogenic tumor
 It is not a true neoplasm but rather is considered to be a
developmental anomaly (hamartoma)
 Two types of odontomas are recognized:
 Compound: this type of odontoma is composed of
multiple small tooth-like structures.
 Complex: this lesion is composed of a conglomerate
mass of enamel and dentin, which bears no anatomic
resemblance to a tooth.
63

64. Odontoma: Clinical Features
 Patient Age: Mostly during the 2nd decade of life
with a mean of 14 years
 Gender Predilection: Approximately equal
 Location: The compound type is more often in
the anterior maxilla while the complex type
occurs more often in the posterior regions of
either jaw
64

65. Odontoma: Radiographic Features
 Early lesions are radiolucent with smooth,
well-defined contours.
 Later a well-defined radiopaque
appearance develops.
 The compound type shows apparent
tooth shapes while the complex type
appears as a uniform opaque mass with
no apparent tooth shapes present.
65

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67. 67

68. 68

69. 69

70. Odontoma: Additional Features
 Most odontomas are small and do not exceed
the size of a normal tooth in the region
 However, large ones do occur and these may
cause expansion of the jaw
 Most odontomas are asymptomatic and as a
result are discovered upon routine radiographic
examination
70

71. Odontoma: Histologic Features
 The compound odontoma is composed of
enamel, dentin and cementum arrange in
recognizable tooth forms; some enamel matrix
may be retained in immature and
hypomineralized specimens
 The complex odontoma is composed of enamel,
dentin and cementum but these tissues are
arranged in a random manner that bears no
morphological resemblance to a tooth
71

72. 72

73. 73

74. Odontoma: Treatment and Prognosis
 Odontomas are treated by simple local
excision and the prognosis is excellent.
74

75. 75

76. Odontogenic
fibroma
76

77. Odontogenic Fibroma: Clinical
Features
 Patient Age: Patients have ranged in age from 9-
80 years old with a mean of 40 years
 Gender Predilection: Females, 7.4:1 in one
study
 Location: In the maxilla, most are located
anterior to the first molar. When in the
mandible, approximately 50 % occur in the
posterior jaw
77

78. 78

79. 79

80. 80

81. Odontogenic Fibroma: Radiographic
Appearance
 The odontogenic fibroma usually appears
as a well-defined, unilocular radiolucency.
It is often associated with the apical area
of an erupted tooth
 Larger lesions are often multilocular
 Many odontogenic fibromas have sclerotic
borders
 Root resorption is common
81

82. 82

83. 83

84. Odontogenic Fibroma: Additional
Features
 Small odontogenic fibromas are usually
asymptomatic
 The larger lesions may be associated with
localized bony expansion of the jaw or
with the loosening of adjacent teeth
84

85. Odontogenic Fibroma: Histologic
Features
 The simple odontogenic fibroma is composed
of stellate fibroblasts arranged in a whorled
pattern with fine collagen fibrils and a lot of
ground substance.
 Foci of odontogenic epithelium may or may not
be present.
 Occasionally, foci of dystrophic calcification may
be present.
85

86. Odontogenic Fibroma:
Histologic Features
 The WHO type odontogenic fibroma appears
as a fairly cellular fibrous connective tissue
with collagen fibers arranged in interlacing
bundles.
 Odontogenic epithelium in the form of long
strands or isolated nests is present
throughout the lesion.
 Calcifications composed of cementoid and/or
dentinoid may be present.
86

87. Odontogenic Fibroma: Treatment
and Prognosis
 The odontogenic fibroma is usually
treated by enucleation and curettage
87

88. Odontogenic Myxoma:
Clinical Features
 Patient Age: 10-50 years with a mean
around 30 years
 Gender Predilection: Reported to be
about equal
 Location: May occur in any area of the
jaws but more common in the mandible.
88

89. 89

90. Odontogenic Myxoma:
Radiographic Features
Radiolucent lesion often with a
multilocular appearance. The
borders may be indistinct.
90

91. 91

92. Odontogenic Myxoma: Histologic
Features
 The tumor is composed of loosely arranged
stellate, spindle-shaped and round cells in an
abundant, loose myxoid stroma with few
collagen bundles.
 Epithelial cells are not required for diagnosis.
 The odontogenic myxoma may be confused with
a chrondromyxoid fibroma or with myxoid
change in an enlarged dental follicle or papilla.
92

93. 93

94. Odontogenic Myxoma: Treatment
and Prognosis
 Small odontogenic myxomas are treated by
curettage, while larger lesions may require
surgical resection as they are not encapsulated
and tend to infiltrate adjacent tissues
 Recurrence rates of up to 25 % are reported
 Overall, the prognosis is good for most
odontogenic myxomas
94

95. Non Odontogenic
Tumours
95

96. Classification
 Fibro-osseous lesions – Ossifying fibroma
Langerhans cell disease
Lesions containing multinucleated giant cells
Neurogemic Tumours – Schwannoma
Neurofibroma
Bone tumours – Osteoma
Chondroma
96

97. Ossifying fibroma
97

98. Ossifying Fibroma –
Clinical Features
 Benign neoplasm characterised by the replacement of normal bone by
fibrous tissue and varying amounts of newly formed bone or cementum
like material
 Presents as painless, slow growing expansile lesion
Occurs mostly in 3rd and 4th decade of life
More frequently in females
Preferred area is the mandible molar – premolar region
98

99. 99

100. Ossifying Fibroma –
Radiographic Features
Well defined radiolucency with varying degrees of calcification. Borders
may be sclerotic
100

101. Ossifying Fibroma –
Treatment and Prognosis
Surgical excision for smaller lesions and marginal mandibulectomy and
segmental resection for bigger tumours
101

102. Langerhans cell
disease
102

103. Langerhans Cell Disease–
Clinical Features
Proliferation of Langerhans cells accompanied by varying number of
eosinophils, other chronic inflammatory cells and multinucleated giant
cells
They present as solitary or multiple lesions in bone. They can cause pain
and tenderness, tooth mobility and bony expansion
103

104. Langerhans Cell Disease–
Clinical Subtypes
Chronic Localised – Eosinophilic granuloma
Acute disseminated Langerhans cell disease – Letterer Siwe disease
Chronic disseminated Langerhans cell disease – Hand-Schuller-Christian
disease
104

105. 105

106. Langerhans Cell Disease–
Radiographic Features
Well defined punched out radiolucencies, sometimes will be ill defined,
which cause floating tooth appearance
106

107. Langerhans Cell Disease–
Treatment and Prognosis
Aggressive local curettage and
resection with minimum 5mm
safety margins, depending on size
Chemotherapy and radiotherapy
have also produced varying
degrees of success
107

108. Central Giant Cell
Granuloma
108

109. Central Giant Cell Granuloma–
Clinical Features
Age: Average of 30 years
Female gender is more preferred
Occurs more in mandible, anterior to 1st molar and frequently crosses
midline
109

110. Central Giant Cell Granuloma–
Clinical Features
Presents as a painless growth, which has good chances to become
secondarily infected
110

111. Central Giant Cell Granuloma–
Radiographic Features
Unilocular or multilocular radiolucency that is well delineated
111

112. Central Giant Cell Granuloma–
Histological Features
Benign proliferation of fibroblasts and multinucleated giant cells
112

113. Central Giant Cell Granuloma–
Treatment and Prognosis
Surgical curettage with a average recurrence of 15-20%
Various non surgical injections – triamcinolone, calcitonin, α-Interferon
have been tried but all of them still require surgical intervention
113

114. Schwannoma
114

115. Schwannoma–
Clinical Features
Benign tumour of neurilemma or nerve sheath
If in bone, exists as a well defined radiolucency
115

116. Schwannoma–
Histological Features
Well encapsulated and predominantly have spindle cells
116

117. Schwannoma–
Treatment
Surgical excision with no recurrence
117

118. Osteoma
118

119. Osteoma–
Clinical Features
Benign tumour of mature compact or cancellous bone
May arise on surface of bone (periosteal osteoma) or centrally within
the bone (endosteal osteoma)
Most common during 2nd – 5th decade with definite male predilection
In face, posterior mandible is most preferred region
119

120. 120

121. Osteoma–
Radiographic Features
Well circumscribed sclerotic radiopaque masses
121

122. Osteoma–
Histologic Features and Treatment
Dense compact bone with narrow
marrow spaces or lamellar
trabaculae of cancellous bone with
fibrofatty marrow spaces
Treatment is surgical excision
122

123. References
Shafer’s Textbook on oral pathology
Peterson’s Principles of oral and maxillofacial surgery
Maxillofacial surgery – Peter Ward Booth
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