Pathology Quiz #14 - Odontogenic Tumours

Front 1

What are the three main types of Odontogenic Tumour origins?

Back 1

- epithelial
- mixed epithelial and mesenchymal
- mesenchymal

Front 2

Which odontogenic tumours are epithelial in origin?

Back 2

- ameloblastoma
- adenomatoid odontogenic tumour (AOT)
- calcifying epithelial odontogenic tumour (CAOT)
- squamous odontogenic tumour
- clear cell odontogenic tumour

Front 3

Which odontogenic tumours are mixed epi and mesenchymal origin?

Back 3

- ameloblastic fibroma
- ameloblastic fibro-odontoma
- ameloblastic fibrosarcoma
- odontoameloblastoma
- odontoma

Front 4

Which odontogenic tumours are mesenchymal in origin?

Back 4

- odontogenic fibroma
- granular cell odontogenic tumour
- odontogenic myxoma
- cementoblastoma

Front 5

What are potential etiologies of AMELOBLASTOMA?

Back 5

- rests of dental lamina
- a developing enamel organ
- epithelium lining of odontogenic cysts
- basal cells of the oral mucosa

Front 6

What are the three clinico-radiologic presentations of ameloblastoma?

Back 6

- conventional solid or multicystic (~86%)
- unicystic (~13%)
- peripheral or extraosseous (~1%)

Front 7

Define "MULTICYSTIC INTRAOSSEOUS AMELOBLASTOMA:

Back 7

- benign (but locally aggressive) neoplasm of odontogenic epithelial origin that histologically resembles the ameloblasts of the enamel organ, except no enamel is produced by lesional cells

Front 8

Most MULTICYSTIC AMELOBLASTOMAS occur where?

Back 8

- mandible
- molar/ramus region (80-85%)

Front 9

Approximately 20% of MULTICYSTIC AMELOBLASTOMA is associated with _______?

Back 9

Impacted tooth - suggesting relationship to dental follicle or dentigerous cyst

Front 10

What is the most typical radiographic feature of AMELOBLASTOMA?

Back 10

- multilocular radiolucency (soap bubble appearance)
- well-defined borders
- not sclerotic
- tendency to infiltrate adjacent trabecular spaces of bone

Front 11

What is the treatment for MULTICYSTIC AMELOBLASTOMA?

Back 11

small lesions - aggressive curettage or small en bloc resection
large lesions - large en bloc resection or segmental resection with reconstruction

margin of resection should be at least 1.0 -1.5 cm past the radiographic limits of the tumour

Front 12

Define UNICYSTIC AMELOBLASTOMA:

Back 12

- most often seen in YOUNGER patients
- 90% of cases in the posterior mandible
- typically a circumscribed radiolucency that surrounds the crown of an unerupted mand. third molar resembling DENTIGEROUS CYST

Front 13

What are the three histological types of UNICYSTIC AMELOBLASTOMA?

Back 13

- luminal ameloblastoma
- intraluminal ameloblastoma
- mural ameloblastoma

Front 14

Define "plexiform unicystic ameloblastoma":

Back 14

- nodules of tumour show plexiform pattern histologically (intraluminal ameloblastoma)

Front 15

What is the TREATMENT of UNICYSTIC AMELOBLASTOMA?

Back 15

LUMINAL/INTRALUMINAL: enucleation and long term follow up
MURAL: local resection as a prophylactic measure and long term follow up

RECURRENCE: 30% after enucleation

Front 16

PERIPHERAL AMELOBLASTOMA probably arises from what?

Back 16

odontogenic epithelium rest beneath the oral mucosa or from the basal epithelial cells of the surface epithelium

Front 17

Define MALIGNANT AMELOBLASTOMA:

Back 17

- rare lesion
- histologically appears to be routine ameloblastoma but it behaves in a malignant fashion

Front 18

Define AMELOBLASTIC CARCINOMA:

Back 18

- rare lesion
- histologically appears malignant and clinically behaves in a malignant fashion

Front 19

Define ADENOMATOID ODONTOGENIC TUMOUR:

Back 19

uncommon benign odontogenic tumour - probably arises from enamel organ epithelium or remnants of dental lamina

Front 20

What are the clinical features of AOT?

Back 20

- younger patients (70% under 20yrs)
- tendency for ANTERIOR portions of jaw
- 2x as often in MAXILLA
- often ASYMPTOMATIC and discovered during ROUTINE RADIOGRAPHIC EXAM to determine why tooth hasn't erupted

Front 21

What are the radiographic features of AOT?

Back 21

- well-circumscribed
- unilocular radiolucency that may contain radiopaque flecks
- separation of roots or displacement of adjacent teeth occur frequently
- when associated with unerupted tooth (most often CANINE) lesion extends apical to CEJ
- less often AOT presents as well-delinated radiolucent lesion located between the roots of erupted teeth

Front 22

What is the treatment of AOT?

Back 22

- enucleation is easy because of capsule
- good prognosis

Front 23

What is another name for PINDBORG TUMOUR?

Back 23

Calcifying Epithelial Odontogenic Tumour (CEOT)

Front 24

Define CEOT?

Back 24

- rare locally aggressive uncommon odontogenic tumour consisting of strands of polyhedral epithelial cells, amyloid staining hyaline deposits, and spherical calcifications (Liesengang rings).

Front 25

What is the histogenesis of CEOT?

Back 25

- unknown
- may be stratum intermedium or dental lamina

Front 26

What are the clinical features of CEOT?

Back 26

- painless
- slow growing swelling is most common presenting sign
- POSTERIOR MANDIBLE favored
- rarely may occur peripherally as gingival mass, most often anterior gingiva

Front 27

What are the radiographic features of CEOT?

Back 27

- unilocular or multilocular radiolucency
- margins often scalloped and usually relatively well defined
- some may have ill-defined periphery or exhibit a cortical border
- may be entirely radiolucent but may contain calcified structures of varying sizes
- occasionally a "driven snow " pattern
- often associated with impacted teeth (most often mand molar)

Front 28

What is the treatment of CEOT?

Back 28

- conservative local resection to include narrow rim of surrounding bone
- overall prognosis is good
- rare cases of malignant or borderline CEOT with metastasis to regional lymph nodes or lung have been reported

Front 29

Define SQUAMOUS ODONTOGENIC TUMOUR (SOT)

Back 29

- rare benign odontogenic neoplasm consisting of islands of bland-appearing squamous epithelium in a fibrous stroma.
- may arise from rest of dental lamina or perhaps from the epithelial rest of Malassez

Front 30

What are the clinical features of SOT?

Back 30

- asymptomatic but tooth mobility and pain may be present
- mean age 37 years
- no preferred site
- several cases have had multiple sites of involvement

Front 31

What are the radiographic features of SOT?

Back 31

- semicircular / triangular radiolucency between two tooth roots
- may or may not be well defined
- vertical periodontal bone loss in some instances

Front 32

What is the treatment of SOT?

Back 32

conservative local excision or curettage
- prognosis good
- multicentric lesions are less aggressive than solitary

Front 33

What are the clinical features of AMELOBLASTIC FIBROMA?

Back 33

- Younger patients (first two decades)
- posterior mandible most common site
- small lesions (ASYMPTO), large lesions painless swelling
- 75% associated with UNERUPTED TOOTH

Front 34

What are the radiographic features of AMELOBLASTIC FIBROMA?

Back 34

- unilocular when small
- multilocular when large
- well-defined or sclerotic

Front 35

What is the treatment of AMELOBLASTIC FIBROMA?

Back 35

- aggressive curettage
- followup

Front 36

Define AMELOBLASTIC FIBRO-ODONTOMA:

Back 36

tumour with general features of an ameloblastic fibroma but that also contains enamel and dentin.

Front 37

What are the clinical features of AMELOBLASTIC FIBRO-ODONTOMA?

Back 37

- usually in children
- most freq in posterior regions of jaws
- commonly asymptomatic
- in most cases an unerupted tooth is present at the margin of the lesion, or the crown of an unerupted tooth may be included in the lesion

Front 38

What are the radiographic features of AMELOBLASTIC FIBRO-ODONTOMA?

Back 38

- well circumscribed
- unilocular or, rarely, multilocular
- radiolucent
- variable amount of calcified material within radiolucency

Front 39

WHat is the treatment of AMELOBLASTIC FIBRO-ODONTOMA?

Back 39

- curettage
- good prognosis

Front 40

What is an AMELOBLASTIC FIBROSARCOMA?

Back 40

Rare malignant counterpart of the ameloblastic fibroma in which ONLY the mesenchymal portion of the lesion shows malignancy
- may arise de novo or from recurrence of a previously diagnosed ameloblastic fibroma or ameloblastic fibroma-odontoma
- more common in mandible
- RADICAL SURGICAL EXCISION treatment of choice

Front 41

Define ODONTOMA:

Back 41

Developmental anomalies rather than true neoplasms

Front 42

Define: HAMARTOMA

Back 42

Developmental anomaly

Front 43

Describe a COMPOUND ODONTOMA:

Back 43

- multiple, small tooth like structures
- anterior maxilla

Front 44

Describe a COMPLEX ODONTOMA:

Back 44

- amorphous radiopaque conglomerations
- posterior regions of either jaw
- irregular

Front 45

How are odontomas treated?

Back 45

simple local excision

Front 46

What are the clinical features of CENTRAL ODONTOGENIC FIBROMA?

Back 46

- female predilection
- Maxilla - ant to first molar
- Mandible - post to first molar
- SOME lesions associated with unerupted tooth
-

Front 47

What is the treatment of CENTRAL ODONTOGENIC FIBROMA?

Back 47

- enucleation / curettage: few recurrences, good prog
- surgical excision for peripheral lesions

Front 48

Define ODONTOGENIC MYXOMA:

Back 48

- benign neoplasm assumed to be of odontogenic origin because it only affects the jaw bones as a central lesion - no other bones

Front 49

What is the recurrence rate of UNICYSTIC AMELOBLASTOMA after enucleation?

Back 49

30%

Front 50

What is the treatment of MURAL AMELOBLASTOMA?

Back 50

local resection

Front 51

How does SQUAMOUS ODONTOGENIC TUMOUR present radiographically?

Back 51

- semicircular or triangular radiolucency between two tooth roots
- may or may not be well defined
- vertical periodontal bone loss sometimes

Front 52

AMELOBLASTIC FIBROMA occurs most commonly where?

Back 52

posterior mandible

Front 53

Which odontogenic tumours are associated with an unerupted tooth?

Back 53

- ameloblastoma
- ameloblastic fibroma
- ameloblastic fibro-odontoma
- adenomatoid odontogenic tumour

Front 54

What are the "virtually pathognomonic" radiographic features of a cemento blastoma?

Back 54

- well circumscribed radiopaque mass
- fine radiolucent border
- fused to the root of a tooth
- usually MAND FIRST MOLAR
- resorption of tooth is typically noted

Front 55

Back 55

AMELOBLASTIC FIBRO-ODONTOMA

Front 56

Back 56

AMELOBLASTIC FIBRO-ODONTOMA

Front 57

DISTRIBUTION AMELOBLASTIC FIBRO-ODONTOMA

Back 57

AMELOBLASTIC FIBRO-ODONTOMA

Front 58

What is this lesion?

Back 58

AMELOBLASTIC FIBROMA

Front 59

What is this lesion?

Back 59

AMELOBLASTIC FIBROMA

Front 60

DISTRIBUTION AMELOBLASTIC FIBROMA

Back 60

AMELOBLASTIC FIBROMA

Front 61

What is this lesion?

Back 61

AMELOBLASTIC FIBROMA

Front 62

AMELOBLASTOMA DISTRIBUTION

Back 62

AMELOBLASTOMA

Front 63

What is this lesion?

Back 63

AMELOBLASTOMA

Front 64

What is this lesion?

Back 64

AMELOBLASTOMA

Front 65

What is this lesion?

Back 65

AMELOBLASTOMA