Benign odontogenic tumors 1

1. ODONTOGENIC TUMORS
OF
ORAL CAVITY
BY:
Aureus Desouza
Post graduate student
Department of Oral Medicine and Radiology

2. CONTENTS
 DEFINTIONS
 INTRODUCTION
 TOOTH GERM
 CLASSFICATION OF ODONTOGENIC TUMORS
 DETAIL OF TUMORS
 SUMMARY

3. DEFINITIONS
 TUMOR – Any enlargement, especially one due to a pathological overgrowth of
tissue
 NEOPLASM – An abnormal mass of tissue, the growth of which exceeds and
is un-coordinated with that of a normal tissue and persists in the same excessive
manner after the cessation of stimuli which evoked the change(Willis,1952)
 BENIGN TUMOR – A condition, tumor , or growth that is not cancerous. This
means that it does not spread to other parts of the body.
 MALIGNANT TUMOR – A neoplastic disease the natural course of which is
fatal
 HAMARTOMA- Abnormal proliferation of tissues native to the part

4. INTRODUCTION
ODONTOGENIC TUMOR / TUMORS OF ODONTOGENIC ORIGIN-:
They represent a spectrum of lesions ranging from malignant(rare) and benign
neoplasms to dental hamartomas, all arising from odontogenic residues, i.e
odontogenic epithelia and /or ectomesenchyme with variable amounts of dental
hard tissues formed generally in the same sequence as in normal tooth
development

5. INTRODUCTION
 Defined as the lesions derived from epithelial or mesenchymal
elements or both that are a part of tooth forming apparatus
According to pathogenesis…..Histologically, they can be
1. Tumors of odontogenic epithelium (only epithelium, no
ectomesenchyme)
2. Mixed odontogenic tumors( epithelium, ectomesenchyme)
3. Tumors of odontogenic ectomesenchyme (ectomesenchyme)

6. TOOTH GERM

8. WHO CLASSFICATION 2005

10. AMELOBLASTOMA
11% of all odontogenic tumors
1% of oral odontogenic epithelial tumors
Second MC odontogenic neoplasm
Described as “ usually unicentric, nonfunctional, intermittent in growth,
anatomically benign and clinically persistent”…. ROBINSON
Defined as “ a slowly growing, locally invasive epithelial odontogenic
tumor of the jaws with a high rate of recurrence if not removed
adequately, but with virtually no tendency to metastasize”…. WHO
2005

11. First recorded , thorough description by - Falkson
SYNONMS
 Admantinoma – Malassez
 Ameloblastoma – Churchill
 Adontomes embryolastiques
 Epithelial odontoma
AMELOBLASTOMA

12. PATHOGENESIS
Derived from :
 Cell rests of enamel organ, either remnants of dental lamina or remnants
of Hertwig’s sheath, epithelial cell rests of Malassez
 Epithelium of odontogenic cysts, particularly the dentigerous cyst or
odontoma
 Disturbances of the developing enamel organ
 Basal cells of surface epithelium of the jaws
Nature of stimulus: not known
AMELOBLASTOMA

13. CLINICAL FEATURES
 Age : 10 to 90 years; max tumors (slightly older ) than mand (Ref:oral
maxfax Surg Clin Am 2004)
 Gender : male = female ( Ref: Shafer’s 5th ed) , men > (Ref: White
and Pharoh 6th ed)
 Race: Blacks > (Ref: White and Pharoh 6th ed)
 Site : Mandible > maxilla
Mandible: Molar-angle ramus ; May extend to symphyseal region
Maxilla: Third molar area ; May extend into the floor of maxillary sinus
and nasal cavity
AMELOBLASTOMA

14. CLINICAL MANIFESTATIONS
A slow growing tumor, painless
 Early stages: asymptomatic, discovered incidentally
Enlarges- Facial deformity, expansion of jaw bone
Expansion ( bony hard, non-tender, ovoid or fusiform)
 Advanced stages: Egg shell crackling (thinning of cortical plate)
May extend into soft tissue
Maxillary lesion – extend into sinus
Tooth mobility (may be)
AMELOBLASTOMA

15. BIOLOGICAL SUBTYPES
 BENIGN
(Solid) ameloblastoma
Cystic( unicystic) ameloblastoma
Peripheral ameloblastoma
 MALIGNANT
Malignant ameloblastoma
Ameloblastic carcinoma
AMELOBLASTOMA

16. CLASSIFICATION
 On the basis of behavioural pattern, anatomical location, radiographic
appearances, histologic features: (Leon Barnes)
1. Unicystic ameloblastoma
2. Multicystic ameloblastoma
3. Desmoplasticameloblastoma
4. Peripheral ameloblastoma
 Histologically,
1. Follicular ameloblastoma
2. Plexiformameloblastoma
3. Acantomatous ameloblastoma
4. Desmoplastic ameloblastoma
5. Granular cell ameloblastoma
6. Basal cell ameloblastoma
AMELOBLASTOMA

17. PATHOLOGICALLY
Mixed patterns are also found. Classification is based on the dominant type
IslandsStrands
Polyhedral/ spindle
cells
Enlarge with cystic
degeneration
Fibrillar cytoplasmic processes contacting
adjacent cells simulates stellate reticulum
FOLLICULAR
AMELOBLASTOMA
Interconnecting strands
Simulates dental lamina stage of
odontogenesis before morpho
and histodifferentiation
PLEXIFORM
AMELOBLASTOMA
AMELOBLASTOMA

18. Squamous cells instead of
stellate reticulum like cells
Island pattern
Parakeratin
deposition
ACANTHOMATOUS
AMELOBLASTOMA
DESMOPLASTIC
AMELOBLASTOMA
More of Strands than
islands
Dense collagenous
stroma
HISTOPATHOLOGY
AMELOBLASTOMA

19. BASAL CELL
AMELOBLASTOMA GRANULAR CELL
AMELOBLASTOMA
Basaloid appearance of cells
Granular cells
HISTOPATHOLOGY
AMELOBLASTOMA

20. RADIOGRAPHIC FEATURES
 Periphery: Well defined (mandible) -> Ill defined (maxilla)
Small lesion- indistinguishable from a cyst
MANDIBLE
Well defined , corticated
MAXILLA
AMELOBLASTOMA
Ill defined

21.  INTERNAL STRUCTURE:
Unilocular/ multilocular
 Desmoplastic: irregular sclerotic bone
UNICYSTIC- completely radiolucent
MULTILOCULATED – posterior mandible
(larger locules)
Curved septa arising from normal
bone
MULTILOCULATED-Anterior
mandible (smaller locules)
Coarse septa
HONEY COMB
SOAP BUBBLE

22. RADIOGRAPHIC FEATURES
 According H. M worth it can present with Four radiographic
appearances
AMELOBLASTOMA
UNICYSTIC
Unilocular radiolucency~ cyst. However,
unlike cyst, it causes a break or
discontinuity in the peripheral cortex and
may even show trabeculae within the
lumen
SPIDER-WEB
MC, where the lesion is seen as a
large radiolucent area with scalloped
borders. From the center of the lumen
coarse strands of trabeculae radiate
peripherally, giving rise to a gross
caricature of a spider

23. RADIOGRAPHIC FEATURES
 According H. M worth it can present with Four radiographic
appearances
AMELOBLASTOMA
HONEY-COMB
Multilocular radiolucency with large
compartments of varying sizes, giving rise
to the soap-bubble appearance, or a multi-
chambered or multi-cystic 'bunch of
grapes' appearance.
SOAP-BUBBLE
Beehive pattern. These are tumors that
have not undergone cystic
degeneration. Hence, multiple small
radiolucencies are seen surrounded by
hexagonal or polygonal thick-walled
bony cortices, giving rise to a
honeycomb appearance.

24. Perforation of
cortical plates
EFFECT ON SURROUNDING STRUCTURES
Expansion of cortical
plates
Unicystic type- expansion of bone
AMELOBLASTOMA

25. Root resorption
Displacement of
teeth( apically MC)
Displacement of teeth
EFFECT ON SURROUNDING STRUCTURES
AMELOBLASTOMA

26. DIFFERENTIAL
DIAGNOSIS
AMELOBLASTOMA

27. Unicystic, pericoronal - DENTIGEROUS CYST
DIFFERENTIAL DIAGNOSIS
Difficult to differentiate without septa

28. Unicystic, not associated with an impacted tooth -
KERATOCYSTIC ODONTOGENIC TUMOR
DIFFERENTIAL DIAGNOSIS
• Well-defined , unicystic
• Expansile
• Not associated with an impacted tooth
• Presence of cortical expansion
• Presence of cortical perforation
• Resorption of tooth
• Displacement of Nerve inferiorly
Features Ameloblastoma KOT
Age 10 to 90 yrs, av 40 Wide range, MC 2nd and
3rd decade
Site Molar , ramus region,
posterior mandible
Posterior body of
mandible and ramus
Cortical expansion B-L A-P > B-L
Cortical Perforation May occur Less common
Resorption of teeth Common Less
Displacement of teeth Common Present but less
Displacement of Nerve Present Present

29. Multicystic variant
DIFFERENTIAL DIAGNOSIS
Features Amelobalsto
ma
KOT O. Myxoma Central
haemangiom
a
Age 10 to 90 yrs,
av 40
Wide range,
MC 2nd and 3rd
decade
Young, 10- 30
yrs
1st decade
Site Molar , ramus
region,
posterior
mandible
Posterior body
of mandible
and ramus
Premolar-
Molar Tooth
bearing area >
Posterior body
and ramus ,
withing the Inf.
Alv canal
Gender M>F M>F F>M F>M 2:1
Features Amelobal
stoma
KOT O. Myxoma Central
haemangioma
Border Well
defined to
ill-defined
Well-
defined,
corticated
Well-defined ,
corticated(poorl
y defined)
Well-defined/ ill
defined
Locules Spider-
web,
Soap-
bubble,
Honey-
comb
Unilocular
mostly,
scalloped
appearanc
e(multilocu
lar)
Multilocular,
tennis racket,
step-ladder
pattern
Multilocular,
honeycomb
Internal
Septa
Straight,
Coarse,
Curved
May
contain
curved
septa
Straight(1/2
mc), Coarse,
Curved
Coarse, dense, well-
defined
Cortical
expansion
B-L A-P> B-L A-P > B-L Present but less
Displacem
ent of teeth
Present(C
ommon)
Present
(Rare)
Present Present (common)
Resorption
of teeth
Present Less Rare Present(often)

30. Features Amelobalstoma Central giant
cell
granuloma
Ossifying
Fibroma
Aneurysmal
Bone Cyst
Age 10 to 90 yrs, av
40
< 20 yrs Young , <20
F>m
<30 yrs
Site Molar , ramus
region, posterior
mandible
Mand>max=2:
1
Young:
Mand:ant to 1st
m
Max:ant to
cuspid
Old:
Post aspect of
jaws
Mnd:Max= 2:1
Inferior to
molars and
premolars,
superior to alv
canal
Mandible:
maxilla= 3: 2;
Molar, ramus
region
Gender M>F - - F>M
DIFFERENTIAL DIAGNOSIS

31. Features Amelobalst
oma
Central
giant cell
granuloma
Ossifying
Fibroma
Aneurysmal Bone
Cyst
Border Well defined
to ill-defined
Ill-
defined(MC),
well defined
Well defined, thin
r/l line (capsule),
occ sclerotic border
Well-defined,circ or
hydraulic shape
Locules Spider-web,
Soap-bubble,
Honey-comb
Subtle
granular str.,
no int st,
Multi-locular
Wispy flocculent
pattern,
Small lesions no st,
Multi-locular
Internal
Septa
Straight,
Coarse,
Curved
Granular,
wispy, ill
defined
septa
Tufts, flocculent
pattern,
amorphous, solid
bone, unif r/o
Wispy, ill-defined
septa, 90 deg to
border
Cortical
expansion
B-
L,Perforation
)
Present,
uneven
B-L , concentric,
Perforation(may
be)
B-L
Displacemen
t of teeth
Present(Com
mon)
Present Present Present
Resorption of
teeth
Present Present
(rare)
Present (Less) Present

32. Features Ameloblastoma Cherubism
Age 10 to 90 yrs, av 40 2 and 6, regresses
Site Molar , ramus region,
posterior mandible
Posterior aspect of
jaws, B/L
Gender M>F
Border Well-defined to ill-
defined
Well defined ,
corticated
Internal Structure Multilocular Multilocular
Septae Straight, Coarse,
Curved
Fine granular, wispy
septae
Effect on teeth Displacement ,
resorption
Teeth are displaced in
ant direction, tooth
buds destroyed
DIFFERENTIAL DIAGNOSIS AMELOBLASTOMA

33. TREATMENT and PROGNOSIS
 unilocular lesions in young patients –enucleation and
curettage
 Solid lesions with high recurrence rate: tumor excision and
partial resection of jaw
 Unicystic has a better prognosis than solid, multicystic

34. Peripheral (Extraosseous)
Ameloblastoma
 1 to 10 % of all ameloblastomas
 Age: Between 40 and 60 years
 Size: Smaller than 1.5 cm to larger lesions
 Site: Mandible1:maxilla = 2:1
 Gingiva, buccal mucosa( rare)
 Posterior gingival and alveolar mucosa
 Superficial alveolar bone may be eroded , no significant involvement
 Clinical feature: Painless, non-ulcerated sessile or pedunculated
gingival or alveolomucosal lesion

35.  c/f non specific.. similiar to fibroma, pyogenic granuloma
Pathogenesis: overlying epithelium or dental lamina
 Histopathologically, acanthomatous> follicular type( ref: shafer’s 5th ed
 Plexiform and follicular > ( Neville 3rd ed)
Treatment: innocous clinical behaviour
 Surgical excission
PERIPHERAL AMELOBLASTOMA

36. UNICYSTIC AMELOBLASTOMA
 Age: younger, 20 to 30yrs
 Site: mandibular third molar region
 Radiographic appearance: unilocular, pericoronal
 May also represent an ameloblastomatous change in a
dentigerous cyst or other type of odontogenic cyst

37. DESMOPLASTIC AMELOBLASTOMA
 4-13% of all ameloblastomas
 Smaller in size than other ameloblastomas
 Age: 17 and 72 years, av 44.7 years
 Gender: Male > Females
 Site: Maxilla = Mandible
 Anterior or premolar regions >; (alveolar region mostly)
 Clinical feature: painless swelling

38. RADIOGRAPHIC FEATURES
 Mixed radiolucent and radiopaque appearance (osseous metaplasia within
Dense fibrous septa of the lesion and not producing a mineralising product)
 Resorption of root(common)
 Displacement of teeth (common)
DESMOPLASTIC AMELOBLASTOMA

39. RADIOGRAPHIC FEATURES
Mixed radiolucent and radiopaque
appearance

40. METASTASIZING AMELOBLASTOMA
 Synonym: Malignant ameloblastoma
 Term used for a tumor that’s shows h/p features of ameloblastoma, both
in primary tumor and metastasizing deposits
 Primary: young age av 30 yrs (jaw/ gingiva)
 Metastatic deposits: After mean interval of 11 yrs
 Site: lung, cervical lymph nodes, extragnathic bones

41.  Reason for occurrence:
1. Intrinsically more aggressive tumor
2. Surgery associated tumor spillage into adjacent or embolism into
lymphatics or blood vessels
 Primary tumor (aggressive) may invade eg. cranial base invasion
before metastasizing to lungs
 H/P: Well-differentiated low grade carcinoma
Treatment: Surgery ( no evidence it improves survival)
 Cervical metastasis: neck dissection
 Lung metastasis: lobectomy
 Chemotherapy: short partial response
METASTASIZING AMELOBLASTOMA

42. AMELOBLASTIC CARCINOMA
 Ameloblastoma that has cytological features of malignancy in the primary
tumor, in a recurrence or in any metastatic deposit
 Markedly aggressive local course, metastases do not occur
 Histopatholgy features :
Features of ameloblastoma +cytologic features of malignancy
(inc N:C, nuclear hyperchromatism, presence of mitoses, necrosis in
tumor islands)
Prognosis : Poor , survival rate 50 % in documented patients

43. RADIOGRAPHIC FEATURES:
 Same as those in non metastasizing ameloblastomas ,
 More aggressive with ill-defined margins
 Cortical destruction
 Perforation of cortical plates
 Expansion of tumor into adjacent tissues
AMELOBLASTIC CARCINOMA

44. Calcifying epithelial odontogenic tumor
 1 % of all odontogenic neoplasms
 Synonym: Pindborg’s tumor
Ameloblastoma of unusual type with calcification
 Pathogenesis: mostly uncertain
1. Stratum intermedium cells
2. Dental lamina

45. CLINICAL FEATURES
 Age : 8 to 92 yrs, av. 42 yrs, Female(older), male( younger)
 Gender: male> females
 Site: Mandible> maxilla 2:1
Premolar- molar area
 Variety: intraosseous (common) , extraosseous
 Association with a tooth: 52% cases
 Clinical manifestation : expansion of jaw, hard on palpation
CEOT

46. RADIOGRAPHIC FEATURES
Periphery
CEOT
Well defined, corticated Ill-defined, irregular
Internal structure
Unilocular Multilocular

47. Radiographic features
1. Pericoronal radiolucency
3. Mixed r/o and r/l lesion
not associated with a tooth
.
2. Pericoronal radiolucency with radiopaque foci
4. Driven snow appearance
5. Completely radiopaque
Radiopaque foci of varying size and density, calcifications close to embedded tooth
CEOT

48. Expansion of jaw with maintained
cortical outline
Displace a developing tooth, prevent its
eruption
Effect on surrounding structure:
CEOT

49. HISTOPATHOLGY
Fibrous stroma with islands and sheets of
polyhedral epithelial cells with abundant
eosinophilic cytoplasm, sharply defined cell
borders and well-developed intercellular
bridges.
Eosinophilic, homogeneous hyalin materia
that is often calcified in the form of
concentric rings is present within or around
the sheets of tumour cells
LIESEGANG RINGS

50. DIFFERENTIAL DIAGNOSIS
Completely radiolucent, well defined, corticated and associated with a
tooth
 Dentigerous cyst (Attached to the CEJ)
 Unicystic ameloblastoma
 Odontogenic keratocyt ( pericoronal variety)
 Early stage ossifying fibroma
 Osteoblastoma
CEOT

51. Mixed radiolucent radiopaque
pericoronal lesions
DIFFERENTIAL DIAGNOSISFeatures CEOT CCOT AOT Ameloblastic
fibro-odotoma
Age 8 to 92 (av 42 yrs) Av 36 yrs 5 to 50 yrs 8 to 92yrs
Gender Slightly M> F M~F M:F= 2:1 M~F
Site Mandible: Maxilla= 2:1 Mandible= Maxilla Maxilla>
mandible
Mandible>Maxilla
Site Premolar-molar area Anterior to first M
Cuspids, incisors
Incisor- Canine-
PM
Premolar-molar
Periphery Corticated/ ill defined Corticated/Ill defined Corticated/
Sclerotic border
Well-defined, corticated
Internal structure Radiopacities(Calcificati
ons ) close to the crown
of the embedded tooth
R/l or with flecks of
calcifications
R/l or with flecks
of calcifications
/like a custer
Majorly R/L , multiple r/o
,round pebble like, r/o
enamel like margin
C/F Painless, jaw expansion
with maintenance of
cortical boundary
Painless, jaw
expansion, cortical
perforation
Painless, jaw
expansion with
maintenance of
cortical boundary
Painless, jaw expansion
A/w unerupted
tooth
75% 52% 75% Most commonly
associated

52. TREATMENT
 Surgical resection- more conservative than ameloblastoma
CEOT

53. ADENOMATOID ODONTOGENIC
TUMOR
 3 to 7 % of all odontogenic tumors
 Hypothesized to be hamartomas, as AOT stop developing about the
time tooth structures complete their development
 Synonyms: adenoameloblastoma, Ameloblastic adenomatoid tumor
 Variants: Intraosseous, Extraosseous
 Intraosseous: Follicular ( 73%) , Extrafollicular
 Extraosseous: small, sessile masses on facial gingiva of maxilla
 Pathogenesis: Enamel organ epithelium , dental lamina

54. CLINICAL FEATURES
 Age : 5 to 50 yrs, av. 16 yrs, Female(older), male( younger)
 Gender: Female: male= 2:1
 Site: Maxilla (75%)> Mandible
Incisor- Canine- Premolar especially canine region
 Variety: intraosseous (common) , extraosseous
 Association with a tooth: 75% cases (follicular variety), discovered
earlier
 Clinical manifestation : Painless swelling, asymmetry, often a/w
missing tooth
AOT

55. VARIANTS OF AOT
E1 TO E4 ----- EXTRAFOLLICULAR SITES
F--- FOLLICULAR
P---- PERIPHERAL

56. RADIOGRAPHIC FEATURES
 Periphery: well-defined. Corticated, sclerotic
AOT
Internal Structure: completely radiolucent
Clusters of ill-defined radiopacities
Calcifications with well-defined borders like
pebbles

57. • Root resorption(rare)
• Expansion of jaw with maintenance if
cortical outline
Inhibition of eruption of tooth Displacement of teeth
EFFECT ON SURROUNDING STRUCTURES

58. DIFFERENTIAL DIAGNOSIS
Completely radiolucent, well defined, corticated and associated with a
tooth
 Dentigerous cyst (Attached to the CEJ)
 Unicystic ameloblastoma
 Odontogenic keratocyt ( pericoronal variety)
 Early stage ossifying fibroma
AOT

59. Mixed radiolucent radiopaque
pericoronal lesions
DIFFERENTIAL DIAGNOSISFeatures CEOT CCOT AOT Ameloblastic
fibro-odotoma
Age 8 to 92 (av 42 yrs) Av 36 yrs 5 to 50 yrs 8 to 92yrs
Gender Slightly M> F M~F M:F= 2:1 M~F
Site Mandible: Maxilla= 2:1 Mandible= Maxilla Maxilla>
mandible
Mandible>Maxilla
Site Premolar-molar area Anterior to first M
Cuspids, incisors
Incisor- Canine-
PM
Premolar-molar
Periphery Corticated/ ill defined Corticated/Ill defined Corticated/
Sclerotic border
Well-defined, corticated
Internal structure Radiopacities(Calcificati
ons ) close to the crown
of the embedded tooth
R/l or with flecks of
calcifications
R/l or with flecks
of calcifications
/like a custer
Majorly R/L , multiple r/o
,round pebble like, r/o
enamel like margin
C/F Painless, jaw expansion
with maintenance of
cortical boundary
Painless, jaw
expansion, cortical
perforation
Painless, jaw
expansion with
maintenance of
cortical boundary
Painless, jaw expansion
A/w unerupted
tooth
75% 52% 75% Most commonly
associated

60. DIFFERENTIAL DIAGNOSIS
 Extrafollicular variety of AOT and CCOT – not be
differentiated
AOT

61. Treatment and Prognosis
 Tumor locally invasive, well encapsulated, easily separated
from bone----- conservative surgical excision
 Recurrence rate: 0.2%
AOT

62. SQUAMOUS ODONTOGENIC
TUMOR
 Rare, First described by Pullon et al (1975)
 Age : 8 to 74 yrs
 Site: Mandible = Maxilla
 Gender: Males = Females ; slightly male (Oral Maxillofacial Surg Clin N Am 16 (2004)
 Clinical Feature: Asymptomatic swelling in alveolar processs, mobility of
teeth
 Pathogenesis: 1. Rests of Malassez (near alveolar process adj to lateral
surface of tooth)
2. gingival surface epithelium
3. Remnants of the dental lamina (near crowns of impacted teeth)

63. RADIOGRAPHIC FEATURES
Triangular, Semi-circular radiolucency between
or along the roots of adjacent teeth
May cause displacement of teeth
SOT
Hyperostotic border
Apex/ Narrow portion towards alveolar crest
If associated with impacted tooth –
pericoronal

64. HISTOPATHOLOGY Islands of squamous epithelium
Microcystic vacuolation
Fibrous dense fibrous connective stroma
SOT

65. TREATMENT
 Maxillary(Porous, spongy ) >Mandibular (Aggressive)
 Enucleation
 Curettage
 and local excision
 Clinically aggressive lesions have been treated by en bloc
excision
PROGNOSIS: Untouched ti

66. KERATOCYSTIC ODONTOGENIC
TUMOR
One –tenth of all cystic lesions in jaw
SYNONYMS: Odontogenic Keratocyst (OKC)
 Keratocystic odontogenic tumour (KCOT)
 Odontogenic keratocystoma
 Primordial cyst
PATHOGENESIS: Dental lamina or its remnants
Basal cells from the overlying oral epithelium
GENETICS: NBCCS or PTCH gene Chromosome 9q22.3-q31

67. CLINICAL FEATURES
AGE: 2nd and 3rd decade of life
GENDER: Males>Females
SITE: Posterior body of mandible( 90% post to canine)
 Ramus( <50%)
 Epi-center superior to inferior alveolar canal
VARIETY: Not contacting teeth( 28%) , (78%) contacting teeth
 May be Pericoronal
KOT

68. CLINICAL FEATURES
SYMPTOMS: Asymptomatic , routine radiographs
 Extremely large ones: asymptomatic, pain (secondary infection) ,
swelling
 Sometimes when palpated, gives a firmer fluctuance (perforation of
cortical plate) than usual bony cyst cause’ filled with keratin (~ doughy
consistency)
 On aspiration, thick, cheesy, yellow substance(keratin)
KOT

69. RADIOGRAPHIC FEATURES
 PERIPHERY AND SHAPE:smooth, round , oval shape , scalloped
KOT
Well- defined , corticated Well- defined, with no cortical border

70. RADIOGRAPHIC FEATURES
 INTERNAL STRUCTURE: Radiolucent (mostly)
curved internal septa (may give multilocular appearance)
KOT

71. RADIOGRAPHIC FEATURES
 EFFECT ON SURROUNDING STRUCTURES: grows along
internal aspect of the jaws( minimal expansion), later
detection
Anterior- Posterior expansion
Less bucco-lingual expansion
KOT

72. RADIOGRAPHIC FEATURES
Expansion may be present when involving
ramus and coronoid process
KOT
• Perforation of cortical plates (rare)
• Displace and resorb teeth (lesser than
dentigerous)
• Displace inferior alveolar nerve inferiorly
• In maxilla, invaginate and occupy entire
maxillary antrum

73. HISTOPATHOLGY
Corrugated para-keratinized
epithelium
5-8 cell layers thick
,basophilic cells
well-defined, often palisaded, basal layer of
columnar or cuboidal cells.
without rete ridges
KOT

75. DIFFERENTIAL DIAGNOSIS
 If the cystic lesion is peri-coronal
Features KOT Dentigerous
cyst
Attachment Apical to CEJ At CEJ
Expansion No/Rare Considerable
Follicle of
associated
tooth
Enlarged less
than
dentigerous
Enlarged more
KOT

76. DIFFERENTIAL DIAGNOSIS
 If multi-locular in appearance
Features KOT Ameloblas
toma
O.myxom
a
Simple
bone cyst
Age 2nd and 3rd
decade
Wide
range
10-30 yrs First 2
decades
Site Mandible>
Max ..post
Posterior
Mandible
Premolar-
Molar
Mandible>
Maxilla
Expansion A-P> Present Mild
Internal
Structure
Unilocular
mostly,
scalloped
appearanc
e(multilocul
ar
Spider-
web, Soap-
bubble,
Honey-
comb
Multilocular
, tennis
racket,
step-ladder
pattern
Scalloped
margins
more
difficult to
detect
Internal
Septa
May
contain
curved
septa
Straight,
Coarse,
Curved
Straight(1/
2 mc),
Coarse,
Curved
KOT

77. RECURRENCE IN KOT
 Pindborg & Hansen (1963) .. Pointed out the aggressive
nature & tendency to recur
 No correlation between size, location of cyst, method of
treatment , cortical perforation
 Recurrence rate - 51% in 6 months or longer
Higher recurrence Lower recurrence
Within 1st 5 yrs of surgery Orthokeratinized type
In asc ramus or angle When enucleated in one
piece when infected
In pts with NBCCS Aggressive surgery
Mutlilocular/ Scalloped
amrgins
Use of Carnoy’s solution

78. Possible reasons for recurrence
1. Tendency to multiplicity, occurrence of satellite cysts and their
retention while enucleation
2. Thin and fragile lining ( Krammer 1963)
3. Formation of Kot from dental lamina or its remnants ( Toller 1967)
4. Proliferation of basal cells of oral mucosa referred to as basal cell
hamartoma ( Stodinger 1983)
5. Higher mitotic rate

79. Factors for classification of KCOT
into KOT
 Behaviour: locally destructive, highly recurrent
 Histopathology: Basal layer of KCOT budding into connective
tissue
 Mitotic figures frequently found in suprabasal layer
 Daughter cysts
 Genetics: PTCH (patched) –TSG-> mutation
 Role of PCTH in KOT
 Two hit hypothesis
 PTCH – gatekeeper gene/ tumor sppressor
 Mutation of one allele with no pehnotypic
 LOH( 2nd hit)
 Dysregulation of oncoproteins cyclin
 Feature of tumorigenic tissue
KOT

80. MALIGNANT EPITHELIAL
ODONTOGENIC TUMORS

81. Primary intraosseous squamous
cell carcinomas
 Central jaw carcinoma derived from odontogenic epithelial remnants’
 SYNONYM : Primary intra-alveolar epidermoid carcinoma
 Subcategories of PIOSCC
1. A solid tumour that invades marrow spaces and induces osseous
resorption
2. SCC arising from the lining of an odontogenic cyst
3. SCC in association with other benign epithelial odontogenic
tumours

82. CLINICAL FEATURES
 GENDER: M:F= 2:1
 AGE: Av age 55 years, few cases during infancy
 SITE: Jaws ; Mandible> Maxilla
 Mandible: body and posterior mandible
 Maxilla: Anterior segment
 No communication with the upper aerodigestive tract mucosa (not
subjected to exposure of the usual carcinogens)
 Tumour destroys the cortex and merges with the surface mucosa,
(difficult to distinguish a PIOSCC from a true carcinoma arising from the
oral mucosa)
 Invasion from an antral primary (excluded)
PIOSCC

83. CLINICAL FEATURES
 Asymptomatic (Most)
 Discovered incidentally
 Facial swelling observed
 Paresthesia (Perineural invasion)
PIOSCC

84. RADIOGRAPHIC FEATURES
 (Osteolytic)The margins of the radiolucency are often
irregular and non-corticated
PIOSCC

85. RADIOGRAPHIC FEATURES
 Larger extensive lesions may show cortical bone expansion
and destruction
TUMOUR SPREAD AND STAGING : Spreads both regionally and distantly
PIOSCC

86. HISTOPATHOLOGY
PIOSCC
• Moderately
differentiated
• Stroma (may or may
not exhibit an
inflammatory
infiltrate)
• Islands of neoplastic
squamous epithelium
(SCC)
Cannot be differentiated
from Metastatic deposits of SCC

87. PIOSCC derived from keratocystic
odontogenic tumour
 Squamous cell carcinoma arising within the jaws without connection
to the oral mucosa in the presence of an a keratocystic odontogenic
tumour (KCOT)
 AGE: 40 years and above
 GENDER: M>F
 SITE: Mandible> mandible
 ETIOLOGY : No known specific predisposing factors

88. CLINICAL FEATURES
 EARLY LESIONS : insidious (usually presenting as a benign
odontogenic cyst ) and the diagnosis of carcinoma is only made after
microscopic examination
 In some , local symptoms at specific sites i.e. pain, swelling,
loosening of teeth, non-healing extraction sockets, and paraesthesia
 Lesions in advanced disease stage frequently appear as overtly
malignant growths with associated ulceration and induration
 Regional lymphadenopathy may also be present
PIOSCC from KOT

89. RADIOGRAPHIC FEATURES
 EARLY LESIONS: indistinguishable from any odontogenic cyst
 In some, the margins of the radiolucent defect appear irregular and
‘ragged’
 LATE LESIONS : Destructive
 A multilocular appearance with cortical destruction and frequent
soft tissue extension characterizes these late-stage neoplasms.
PIOSCC from KOT

90. HISTOPATHOLOGY
 The histological appearance of this lesion is typically that of a
keratinizing well-differentiated squamous cell carcinoma in
conjunction with KCOT.
Severe dysplasia with transition
to an invasive focally keratinized
squamous cell carcinoma.
PIOSCC from KOT

91. PIOSCC derived from odontogenic
cysts
 A squamous cell carcinoma arising within the jaws without connection to
the oral mucosa, and in the presence of an odontogenic cyst
 GENDER :Male :Female =2:1
 SITE: Mandible> Maxilla
 CLINICAL FEATURES : Pain, paraesthesia or anaesthesia of the lower
lip
 RADIOGRAPHIC FEATURES: May mimic any type of odontogenic cyst
Other than keratocystic odontogenic tumour

92. HISTOPATHOLOGY
 Lined by any type of epithelium that can be seen in odontogenic cysts in
association with a squamous cell carcinoma
 Various degrees of dysplasia in the epithelial cyst lining
 The architecture of verrucous hyperplasia or verrucous carcinoma may
be present, as well
PROGNOSIS AND PREDICTIVE FACTORS :
 PIOSCC associated with an impacted lower third molar seems to have a
favourable prognosis; although the number of reported cases is small.
PIOSCC from other
O.Tumors

93. Clear cell odontogenic carcinoma
 Clear cell odontogenic carcinoma (CCOC) is characterized
by sheets and islands of vacuolated and clear cells
 HISTORY: Was called clear cell ameloblastoma and clear
cell odontogenic tumour
 Was considered a benign tumour in the previous WHO
classification of 1992

94. CLINICAL FEATURES
 GENDER : Females > Males
 AGE: Close to 60 years, range 17-89
 SITE: Mandible> Maxilla
 Symptoms :Swelling of the jaws and loosening of teeth
 RADIOGRAPHIC FEATURES :Aggressive tumour growth results in an
ill-defined radiolucency, and root resorption may occur
CCOCC

95. HISTOPATHOLOGY
CCOCC
• Sheets of polygonal cells with central
clear or faintly eosinophilic cytoplasm,
well defined cell membrane and dark,
peripheral or central nucleus.
• Peripheral cells abutting on narrow
fibrous bands are palisaded.
• Tumour cells show clear cytoplasm with
apical nucleus.
Biphasic tumour pattern with sheets of
clear cells and irregular cords and strands
of dark, basaloid cells, intersected by
narrow bands of fibrous stroma

96. TREATMENT AND PROGNOSIS
 Aggressive growth pattern and frequently recurs
 The tumour can metastasize to regional lymph nodes and lungs, as well
as to bone, and tumour progression may even cause tumour related
death
 Resection with tumour-free margins is the treatment of choice, and
long-term follow-up is mandatory
 Adjuvant radiotherapy is a rational option for tumours that have eroded
cortical bone
CCOCC

97. GHOST CELL ODONTOGENIC
CARCINOMA
 Malignant odontogenic epithelial tumour with features of calcifying
cystic odontogenic tumour and/or dentinogenic ghost cell tumour
SYNONYMS:
 Calcifying ghost cell odontogenic carcinoma
 Malignant epithelial odontogenic ghost cell tumour
 Carcinoma arising in a calcifying odontogenic cyst
 Aggressive epithelial ghost cell odontogenic tumour
 Malignant calcifying odontogenic cyst
 Malignant calcifying ghost cell odontogenic tumour

98. FEATURES
 GENDER : Male :Female =2:1
 AGE: 13-72 years ,av 4th decade
 SITE : Maxilla :Mandible (2:1)
 either at anterior or posterior area, corresponding to the site
distribution of the calcifying odontogenic cyst
 CLINICAL FEATURES : Swelling, often with paraesthesia
GCOCC

99. RADIOGRAPHIC FEATURES:
 Poorly demarcated, osteolytic radiolucency with some
radiopaque material
 Displacement of tooth roots is common
 Tooth impaction and root resorption
 Large lesions in the maxilla often destroy the sinus wall, grow
into the nasal and orbital cavities, and extend to adjacent
structures
GCOCC

100. HISTOPATHOLOGY
• Rounded epithelial islands in a
fibrous stroma
• The epithelial cells are either small,
rounded with dark nuclei or larger
with vesicular nuclei
• Ghost cells are found in varying
numbers either isolated or in clusters
Dysplastic dentin may be present
It can either be an admixture of benign
and malignant tumors
Or it exists separately

101. PROGNOSIS
 Unpredictable due to a wide spectrum of growth patterns
 Slowly growing, locally invasive tumour to a highly
aggressive
 Rapidly growing neoplasm with local recurrence and
metastasis
 The overall five-year survival rate is 73%
 Recurrences are common

102. SUMMARY

103. WHO CLASSFICATION 2005

104. 0-25 yrs More than 40
AOT CEOT
Ameloblastic Fibroma Ameloblastoma
Ameloblastic Fibro-odontoma SOT
Odontoma O.Myxoma
Ameloblastic Odontoma
Tumors Based on age predilection
Tumors Based on gender predilection
Male Females
Ameloblastoma AOT
Ameloblastic Fibroma SOT
Ameloblastic-Fibro-odontoma O.Myxoma
Ameloblastic Odontoma
CEOT

105. Tumors Based on Site of predilection
Mandible maxilla
Ameloblastoma AOT
Ameloblastic Odontoma CEOT
Odontogenic Myxoma Ameloblastic-Fibroodontoma
Calcifying odontogenic fibroma SOT

106. Unilocular , Radiolucenct, Pericoronal(a/w tooth)
Dentigerous cyst
Mural Ameloblastoma
Keratocystic Odontogenic tumor
Adenomatoid Odontogenic Tumor (early stage)
Amelobalstic Fibroma
Multilocular, Radilucenct, associated with teeth
Ameloblastoma
Keratocystic Odontogenic tumor
Odontogenic Myxoma

107. Odontoma(intermediate Stage)
Adenomatoid Odontogenic Tumor
CEOC
CEOT
Ameloblastic Fibro-odontoma
Ameloblastic odontoma
Amelobalstic Fibrodentinoma
Mixed radiolucent an dradiopaque associated with teeth

108. SOAP BUBBLE APPEARANCE
Hemangioma
Aneursymal Bone Cyst
Cherubism
Ameloblastoma
Giant cell Lesion of Hyperparathyroidsm
Central giant Cell granuloma
Keratocystic Odontogenic tumor
AV malformation
Honey Comb Appearance
Ameloblastoma
Central Hemangioma of bone
Driven Snow AppearanceTennis racket appearance
Odontogenic Myxoma Calcifying Odontogenic Tumor