Odontogenic Tumors

1. Odontogenic Tumors

2. Odontogenic Tumors
• Odontogenic tumors are derived from the epithelial
and/or mesenchymal remnants of the tooth-forming
apparatus.
• Found exclusively in the mandible and maxilla (and
occasionally in the gingiva).
• The origin and pathogenesis is unknown.
• Clinically, odontogenic tumors are typically
asymptomatic
– although they may cause
• jaw expansion, movement of teeth, root resorption, and bone loss.

4. Odontogenic Tumors
• EPITHELIAL TUMORS
• MESENCHYMAL TUMORS
• MIXED (EPITHELIAL AND MESENCHYMAL) TUMORS

5. EPITHELIAL TUMORS
• Ameloblastoma
• Calcifying Epithelial Odontogenic Tumor
(Pindborg Tumor)
• Adenomatoid Odontogenic Tumor
• Squamous Odontogenic Tumor
• Clear Cell Odontogenic Tumor (Carcinoma)

6. MESENCHYMAL TUMORS
• Odontogenic Myxoma
• Central Odontogenic Fibroma
• Cementifying Fibroma
• Cementoblastoma
• Periapical Cemento-osseous Dysplasia

7. MIXED (EPITHELIAL AND ESENCHYMAL)
TUMORS
• Ameloblastic Fibroma and
Ameloblastic Fibro-odontoma
• Odontoma

8. EPITHELIAL TUMORS
•Ameloblastoma
•Calcifying Epithelial Odontogenic Tumor (Pindborg Tumor)
•Adenomatoid Odontogenic Tumor
•Squamous Odontogenic Tumor
•Clear Cell Odontogenic Tumor (Carcinoma)

9. AMELOBLASTOMA
EPITHELIAL TUMOR

10. Epithelial Tumor: Ameloblastoma
• This neoplasm originates within the
mandible or maxilla from epithelium
involved in the formation of teeth.
• Less common: within the gingiva of
tooth-bearing areas.

11. Epithelial Sources
• Potential epithelial sources includes:
– Enamel organ
– Odontogenic rests (rests of Malassez, rests of
Serres)
– Reduced enamel epithelium
– Epithelial lining of odontogenic cysts

12. AMELOBLASTOMA:
PATHOGENETIC MECHANISMS
• CELL CYCLE–RELATED
FACTORS
• Low proliferation rate; few
cells in cell cycle based on
low Ki-67 expression
• Antiapoptotic proteins
expressed; overexpression
of Bcl-2 and Bcl-xL
• Some positive p53 staining;
probably wild-type protein
inactivated by MDM2
binding
• TNF-α expression
• INTERFACE FACTORS
• Invasive properties
enhanced
• Altered laminin 5 at
interface
• Expression of FGF and
interleukins (1 and 6)
• Overexpression of
proteinases (MMPs 9 and
20; EMSP1)

13. AMELOBLASTOMA:
PATHOGENETIC MECHANISMS
• Ameloblastoma
exhibiting
overexpression
(brown
cytoplasmic
stain) of
antiapoptotic
protein Bcl-2.

14. AMELOBLASTOMA: CLINICAL FEATURES
• Benign, aggressive tumor that
is invasive and persistent
• Sometimes called solid or
multicystic ameloblastoma
• Adults most commonly
affected
• Broad age range; mean age,
40 years

15. AMELOBLASTOMA:
CLINICAL FEATURES
Ameloblastoma of the mandible
with oral presentation.

16. AMELOBLASTOMA:
CLINICAL FEATURES
• Mandibular molar-ramus most
commonly affected site
• Always radiolucent
• Unilocular or multilocular
• Slow-growing and typically well
defined radiographically
• Treated by surgical excision to
resection
• Recurrence rate higher with
conservative treatment
Ameloblastoma in an edentulous
anterior mandible. Occlusal view
shows a destructive multilocular
lesion.

17. Histopathology
• All subtypes mimic
enamel organ
• Peripheral palisades
and budding
• No hard tissue
formation
• No clinical significance
to subtypes
Ameloblastoma, follicular pattern.

18. AMELOBLASTOMA:
BIOLOGICAL SUBTYPES
• (Solid)
ameloblastoma
• Cystic (unicystic)
ameloblastoma
• Peripheral
ameloblastoma
• Malignant
ameloblastoma
• Ameloblastic
carcinoma
Cystic ameloblastoma with a loculated
appearance in retromolar mandibular bone.

19. PERIPHERAL
AMELOBLASTOMA
• Ameloblastoma developing in gingival soft tissue
• May originate from gingival epithelium
• Typically does not invade underlying bone
• Older adults most commonly affected
• Presents as a painless
gingival mass
• Common in Mandibular
gingiva
• Treated with local excision;
rarely recurs

20. CYSTIC (UNICYSTIC) AMELOBLASTOMA
• CLINICAL FEATURES
– Multilocularity and cortical perforation
(25% of cases)
• HISTOPATHOLOGY
– Thin, nonkeratinized epithelium
– Basal palisading
– Spongiosis
– Epithelial invaginations
– Subepithelial hyalinization
• MICROSCOPIC PATTERNS
– Simple cystic intraluminal growth
– Simple cystic with mural invasion
• TREATMENT
– Excision
– Curettage; recurrence rate as high as
40% (seen as late as 9 years after
surgery)
Cystic ameloblastoma with a spongiotic
epithelial lining.

21. Malignant ameloblastoma
Ameloblastic carcinoma
• Malignant variants of ameloblastomas may
rarely be encountered.
• These lesions occur in a relatively young age
group (thirties)
• It appear in the mandible more commonly than
in the maxilla.
• By definition, these are lesions that metastasize
to local lymph nodes or distant organs.

22. Treatment and Prognosis
No single standard type of therapy can be advocated for patients with ameloblastoma
• Solid ameloblastoma
– requires at least surgical
excision
• Cystic ameloblastomas
– may be treated less
aggressively, but with the
knowledge that recurrences
are often associated with
simple curettage
• Peripheral
ameloblastomas
– should be treated in a more
conservative fashion.
• Malignant lesions
– should be managed as
carcinomas.
• Cystic ameloblastoma
– treatment options can range
from enucleation to resection

23. Calcifying Epithelial Odontogenic
Tumor (Pindborg Tumor)
EPITHELIAL TUMOR

24. Calcifying epithelial odontogenic tumor
(CEOT)
• also known as Pindborg tumor
• after the oral pathologist Jens Jørgen Pindborg
• benign tumor of odontogenic origin that shares
many clinical features with ameloblastoma
• Microscopically, however, there is no resemblance to
ameloblastoma, and radiographically distinct differences
noted

25. Pindborg Tumor
• HISTOGENESIS:
– Unknown;
– may be dental lamina or stratum intermedium

26. Pindborg Tumor: Clinical Features
• Adults 30 to 50 years old
• no gender predilection
• mandible ˃ maxilla
• predilection for the molar-ramus region
– but any sites could be affected.
• Jaw expansion
• Associated with impacted tooth

27. Diagnostic
• Jaw expansion or incidental observation
on a routine radiographic survey is the
usual way in which these lesions are
discovered.
• Radiographically, the lesions are often
associated with impacted teeth.

28. Pindborg: Radiograph
• Often associated with
impacted teeth
• May be unilocular or
multilocular
• Small loculations
termed honeycomb
to describe this lucent
pattern

29. Pindborg: Radiograph

30. Pindborg Tumor: Histopathology
• HISTOPATHOLOGY:
– Epithelioid
strands/nests/sheets
– Amyloid and
calcification
– Rare clear cell variant
Calcifying epithelial odontogenic
tumor showing nuclear atypia,
amyloid, and calcification.

31. Treatment
• Various forms of surgery, ranging from
enucleation to resection, have been used
to treat CEOTs.

32. ADENOMATOID
ODONTOGENIC TUMOR
EPITHELIAL

33. Adenomatoid odontogenic tumor
(AOT)
• was formerly termed adenoameloblastoma
– because it was believed to be a subtype of ameloblastoma that
contains ductlike or glandlike structures
• Epithelial odontogenic hamartoma containing
pseudoducts and enameloid
• Age range—between 5 and 30
– with most cases on the 20s’
• More common in females than males
• Generally in association with the crowns of impacted
teeth

34. AOT Three variants
– Follicular (73% of cases)
• a well-circumscribed unilocular lesion that usually appears
around the crown of an impacted tooth
– Extrafollicular (24%)
• The extrafollicular type usually presents as a well-defined
unilocular radiolucency above, between, or superimposed
over the roots of an unerupted tooth.
– Peripheral (3%)
• The peripheral type is characterized by a painless, nontender
gingival swelling

35. Radiograph
• Adenomatoid
odontogenic
tumor
surrounding the
crown of an
impacted tooth.

36. Treatment
• Conservative treatment (enucleation) is all
that is required.
• AOTs are benign, encapsulated lesions
that do not recur.

37. SQUAMOUS ODONTOGENIC
TUMOR
EPITHELIAL

38. Squamous Odontogenic Tumor
• The lesion is believed to be derived from
neoplastic transformation of the rests of
Malassez.
• It occurs in mandible and the maxilla with equal
frequency
• Favoring the anterior region of the maxilla and the posterior
region of the mandible.
• The age range from the second through seventh
decades, with a mean age of 40 years.

39. Clinical Features
• Patients usually experience
no symptoms, although
tenderness and tooth
mobility have been
reported.
• Radiographically, this
lesion typically is a well-
circumscribed, often
semilunar lesion associated
with the cervical region of
roots of teeth.

40. Histopathology
Microscopically, it has some similarity to ameloblastoma,
although it lacks the columnar peripherally palisaded
layer of epithelial cells
Squamous odontogenic tumor. A and B, Bland proliferation of
squamous islands.

41. Treatment
• Squamous odontogenic tumors have
some invasive capacity and infrequently
recur after conservative therapy.
• Curettage or excision is the treatment of
choice.

42. CLEAR CELL ODONTOGENIC
TUMOR (CARCINOMA)
EPITHELIAL

43. Clear cell odontogenic tumor
(carcinoma)
• Clear cell odontogenic tumor (carcinoma)
is a rare neoplasm of the mandible and
maxilla
• Histogenesis:
– Unknown; probably odontogenic

44. Clinical Features
• Age over 60 years
• women affected more often than men
• Site: Either jaw
• Occasionally painful

45. Clear cell odontogenic tumor
(carcinoma)
• HISTOPATHOLOGY:
• Nests/cords of clear
cells, some palisades
• Some glycogen; mucin
negative
• poorly circumscribed
neoplasm composed of
sheets of cells with
relatively clear cytoplasm Clear cell odontogenic tumor as nests of
odontogenic epithelium with relatively
clear cytoplasm.

46. CCOT: behavior
• The rate of recurrence may be as high as
50%.
• Metastases to lung and to regional lymph
nodes have been reported.

47. MESENCHYMAL TUMORS
• Odontogenic Myxoma
•Central Odontogenic Fibroma
•Cementoblastoma
•Periapical Cemento-osseous Dysplasia

48. ODONTOGENIC MYXOMA
MESENCHYMAL TUMOR

49. Odontogenic Myxoma
• Myxoma is a benign tumor of connective
tissue containing mucous or gelatinous
material.
• Odontogenic myxoma is a benign
mesenchymal lesion that mimics
microscopically the dental pulp or follicular
connective tissue.

50. Clinical features
• Mean age of about 30 years
– The age range in which this lesion appears
extends from 10 to 50 years
• No gender predilection
• Seen anywhere in the mandible and
maxilla with about equal frequency

51. Radiograph
• Always lucent
• although the pattern may
be quite variable.
• It may appear as a well-
circumscribed or diffuse
lesion.
• It often is multilocular
with a honeycomb
pattern Odontogenic myxoma showing
characteristic multilocularity.

52. Hystopathology
• Composed of bland,
relatively acellular
myxomatous
connective tissue
• Benign fibroblasts and
myofibroblasts with
variable amounts of
collagen are found in
a
mucopolysaccharide
matrix.
Odontogenic myxoma exhibiting typical
bland myxoid appearance.

53. Treatment
• Surgical excision is the treatment of choice.
– Because of its classical loose, gelatinous consistency,
curettage usually results in incomplete removal of the
neoplasm.
• Have a moderate recurrence rate
• Prognosis is very good.
• Repeated surgical procedures do not appear to
stimulate growth or metastasis.

54. CENTRAL ODONTOGENIC
FIBROMA
MESENCHYMAL TUMOR

55. Central Odontogenic Fibroma
• Fibromas (or fibroid tumors or fibroids)
• Central odontogenic fibroma is a rare
ectomesenchymal tumor that is regarded
as the central counterpart to peripheral
odontogenic fibroma
• 2 : 1 female predilection

56. Radiograph
• It results in a
radiolucent lesion
that usually is
multilocular, often
causing cortical
expansion

57. Treatment
• Treatment: enucleation or excision
• Recurrence is very uncommon.
– An exception in terms of recurrence potential
is the odontogenic fibroma with a central giant
cell lesion component, in which a 23% rate of
recurrence has been reported.

58. CEMENTOBLASTOMA
MESENCHYMAL TUMOR

59. Cementoblastoma
• also known as true
cementoma
• is a rare benign neoplasm
of cementoblasts
– microscopically resembles
an osteoblastoma but is
connected or fused to the
root of a tooth .

60. Clinical features
• There is no gender predilection
• Benign fibro-osseous jaw lesion
• Young adults, typically before 25
• mandible > maxilla
• Attached to and replaces tooth root
• Periodontal ligament space
surrounds lesion

61. Radiograph
• This neoplasm is
an opaque lesion
that replaces the
root of the tooth
• It usually is
surrounded by a
thick and uniform
radiolucent ring
that is contiguous
with the periodontal
ligament space.

62. Histopathology
• Histopathology.
This lesion
appears
microscopically as
a dense mass of
mineralized
cementum-like
material with
numerous reversal
lines.
Cementoblastoma with a periphery showing
numerous pale cementoblasts (left) against a
dense network of cementum.

63. Treatment
• Neoplasm removal with
involved tooth.
• Recurrence is not seen.
Bone relief typically is
required to remove this
well-circumscribed
mass
Postsurgical orthopantomogram showing
marginally resected right side the mandible
stabilized with reconstruction plate

64. PERIAPICAL CEMENTO-
OSSEOUS DYSPLASIA
MESENCHYMAL TUMOR

65. Periapical Cemento-osseous Dysplasia
• Reactive or dysplastic process, rather than a
neoplastic.
• This lesion appears to be an unusual response
of periapical bone and cementum to some
undetermined local factor
• When not associated with a tooth apex, the term
focal cemento-osseous dysplasia is used.

66. CLINICAL FEATURES
• Reactive, unknown
stimulus, teeth vital
• Common in anterior
mandible of adults
– appears in middle age
( 40 years) and rarely∼
before the age of 20
• No symptoms
• Progresses from lucent
to opaque lesion

67. Radiograph
• Appears first as a periapical
lucency that is continuous with
the periodontal ligament space.
• As the condition progresses or
matures, the lucent lesion
develops into a mixed or mottled
pattern because of bone repair
• In its final stage, the tumor
appears as a solid, opaque mass
that often is surrounded by a thin,
lucent ring

68. Radiograph
Periapical cemento-osseous
dysplasia, radiopaque phase.
Florid cemento-osseous
dysplasia of the mandible.
Periapical cemento-
osseous dysplasia,
radiolucent phase.

69. Treatment
• No treatment is required for periapical
cemento-osseous dysplasia or FCOD.
• Once the opaque stage is reached, the lesion
usually stabilizes and causes no
complications.
• Because teeth remain vital throughout the entire process,
they should not be extracted, and endodontic procedures
should not be performed.

70. MIXED (EPITHELIAL AND
MESENCHYMAL) TUMORS
•Ameloblastic Fibroma and Ameloblastic Fibro-odontoma
•Odontoma

71. AMELOBLASTIC FIBROMA AND
AMELOBLASTIC FIBRO-ODONTOMA
MIXED (EPITHELIAL AND MESENCHYMAL) TUMORS

72. Ameloblastic Fibroma and
Ameloblastic Fibro-odontoma
• Considered together
– because they appear to be slight variations of
the same benign neoplastic process
• Both are benign mixed odontogenic
tumors
– composed of neoplastic epithelium and
mesenchyme with microscopically identical
soft tissue components.

73. Clinical Features
• These neoplasms occur predominantly in
children and young adults.
• The mean age is about 12 years, and the upper
age limit is around 40 years.
• The mandibular molar-ramus area is the
favored location for these lesions
• although they may appear in any region.
• There is no gender predilection.

74. Radiograph
• These lesions are well
circumscribed and
usually are
surrounded by a
sclerotic margin.
• ameloblastic fibroma
is completely lucent
radiographically
Ameloblastic fibroma of the left
mandible. The lesion is a well-
circumscribed lucency.

75. Radiograph
• They may be
unilocular or
multilocular and may
be associated with
the crown of an
impacted tooth.
Ameloblastic fibro-odontoma as
represented in the right molar-
ramus area of this skull
radiograph. Note odontoma
between impacted teeth.

76. Histopathology
• These lesions are lobulated in general
configuration and usually are surrounded by a
fibrous capsule.
Ameloblastic fibroma. A, Lobular circumscribed pattern. B, Myxoid stroma and odontogenic strands

77. Treatment
• Because of tumor encapsulation and the general
lack of invasive capacity, this lesion is treated
through a conservative surgical procedure such
as curettage or excision.
• Recurrences have been documented

78. ODONTOMA
MIXED (EPITHELIAL AND MESENCHYMAL) TUMORS

79. Odontoma
• Odontomas are mixed odontogenic tumors, in
that they are composed of both epithelial and
mesenchymal dental hard tissues.
• These fully differentiated tissues are a
composite of enamel and dentin.
• Biologically, odontomas can be regarded as
hamartomas rather than neoplasms.

80. General Configurations
• Asymptomatic
– Discovered on routine radiographic examination or
when it blocks eruption of a tooth
• Compound type
– Composed of multiple miniature teeth
– Most commonly found in anterior maxilla
• Complex type
– Conglomerate mass of enamel and dentin
– Most commonly found in the posterior jaws

81. Clinical Features
• Odontomas are lesions of children and
young adults; most are discovered in the
second decade of life
• The maxilla is affected slightly more often
than the mandible.
• There is also a tendency for compound
odontomas to occur in the anterior jaws,
and for complex odontomas to occur in
the posterior jaws.

82. Clinical Features
• Clinical signs
suggestive of an
odontoma include
a retained
deciduous tooth,
an impacted
tooth, and
alveolar swelling
A, Compound odontoma blocking the eruption of a
permanent tooth.
B, Retained deciduous tooth overlying compound
odontoma.

83. Radiograph
• Compound
odontomas typically
appear as numerous
tiny teeth in a single
focus.
• This focus is typically
found in a tooth-
bearing area,
between roots or over
the crown of an
impacted tooth

84. Radiograph
• Complex odontoma
occupying most of the
mandibular ramus.

85. Histopathology
• Normal-appearing
enamel, dentin,
cementum, and pulp
may be seen in these
lesions. A prominent
enamel matrix and the
associated enamel
organ are often seen
before final maturation
of hard tissues.
Complex odontoma (decalcified)
showing a network of pink dentin and
islands of bluish enamel matrix.

86. Treatment
• Odontomas have very limited growth potential,
although an occasional complex odontoma may
achieve considerable mass. Enucleation is
curative, and recurrence is not a problem.

87. THANK YOU