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Flashcards in Odontogenic Tumors Deck (44):
1

Odontogenic Tumors: 3 Tissue categories of origin

1. Odontogenic Epithelium
2. Mesenchymal
3. Mixed

2

Tumors of Odontogenic Epithelium

• Ameloblastoma
• Adenomatoid odontogenic tumor
• Calcifying epithelial odontogenic tumor
• Squamous odontogenic tumor

3

Ameloblastoma types

• Multicystic (solid conventional) – 86%
• Unicystic – 13%
• Peripheral – 1%

4

Ameloblastoma stats

• Usually 3rd to 7th decades, no gender predilection
• 85% mandible (molar/ramus most common), 15% maxilla
(usually posterior)

5

Ameloblastoma - Radiographic

• Multilocular radiolucency usually; soap bubble (large loculations),
honeycomb (small loculations)
• Buccal and lingual cortical expansion
• Often associated with an unerupted tooth (3rd molar)
• Margins may show irregular scalloping

6

Ameloblastoma and roots

Resorption of
adjacent tooth
roots is
common

7

Ameloblastoma – Treatment and Prognosis

• Enucleation and curettage (recurrence 50% to 90%)
• Marginal resection (recurrence up to 15%)
• En bloc resection, with at least 1 cm clear margins (highest cure rate)
• Radiation therapy not recommended, except to control nonresectable
tumors.

8

Desmoplastic Ameloblastoma

• The exception to the rules for conventional
ameloblastoma
– One of several histologic subtypes of ameloblastoma
– Preference for anterior jaws, most often maxilla
– Radiographically resembles a fibro-osseous lesion
– Mixed radiolucent/radiopaque appearance due to osseous
metaplasia within dense fibrous septa
– Varying opinions regarding aggressiveness of tumor and
recommended treatment

9

Unicystic Ameloblastoma

• 50% diagnosed during the second decade of life
• Over 90% are found in the mandible, usually posterior
• Circumscribed radiolucency, often surrounding the crown of an
unerupted third molar, similar to dentigerous cyst

10

Unicystic Ameloblastoma Dx guidlines

To be diagnosed as unicystic, the
ameloblastoma must be unicystic grossly,
radiographically, and histologically

11

Unicystic Ameloblastoma – Treatment and
Prognosis

• Enucleation is most common, although if the tumor is found to be
mural (satellites of ameloblastic epithelium within wall of cyst),
further treatment is indicated
• 10% to 20% recurrence after enucleation

12

Peripheral Ameloblastoma

• 1% of ameloblastomas
• GUM BUMP - Painless, non-ulcerated, sessile or pedunculated lesion
on gingiva or alveolar mucosa; usually posterior, more common in
mandible
• Average age 52
• Innocuous behavior. Local surgical excision recommended, with 15%
to 20% recurrence initially; second recurrence is rare.
• Rule out central ameloblastoma

13

Gum Bump Differential

Pyogenic granuloma
Fibroma
Ossifying fibroma
Peripheral giant cell
granuloma
Parulis
Others: Peripheral
odontogenic fibroma,
peripheral ameloblastoma

14

Malignant Ameloblastoma

• Less than 1% of all ameloblastomas
• Metastasis, with secondary tumors exhibiting histology similar to
primary tumor (benign cytology under the microscope)
• Mets to lungs most common… aspiration or implant mets. Metastasis
may also occur via blood or lymphatic channels
• Poor prognosis

15

Ameloblastic Carcinoma

• Cytologic features of malignancy either in primary or secondary
tumors (microscopically ugly)
• More aggressive, with ill-defined margins, destruction of cortex, and
extension into soft tissue
• Poor prognosis

16

Adenomatoid Odontogenic Tumor (AOT)

• 3%-7% of odontogenic tumors
• “Two thirds tumor”: Female, young (ages 10 to 19), anterior jaws,
maxillary, associated with impacted tooth, radiopacities
• Most often asymptomatic, less than 3 cm. May cause painless bony
expansion if large

17

Adenomatoid
Odontogenic Tumor

2/3’s tumor:
Female
Anterior
Maxillary
Young
Canine tooth

18

Adenomatoid Odontogenic Tumor – Radiographic
Features

• Unilocular radiolucency
• May contain fine calcifications – snowflake calcifications (mixed
RL/RO DDX)
• “Follicular” - associated with crown of unerupted tooth
• “Extrafollicular” – associated with or between tooth roots

19

Adenomatoid Odontogenic Tumor – Treatment
and Prognosis

• Enucleates very easily due to thick capsule
• Recurrence after enucleation is rare
• No reports of aggressiveness

20

Calcifying Epithelial Odontogenic Tumor
(CEOT, aka Pindborg Tumor)

• Less than 1% of odontogenic tumors, less than 200 reported cases
• Wide age range, most common between 30 and 50 years
• No gender predilection
• Two thirds of cases reported in the mandible, usually posterior
• Painless, slow growth

21

Calcifying Epithelial Odontogenic Tumor
(CEOT) - Radiographic

• Radiolucent defect, most often multilocular
• Margins may be scalloped
• Frequent association with an impacted tooth, usually a mandibular
third molar
• Often contains calcifications that vary in density and size,
concentrated around crown of impacted tooth – amyloid material and
Leisegang calcifications

22

Calcifying Epithelial Odontogenic Tumor –
Treatment and Prognosis

• Conservative resection, including a narrow rim of surrounding bone
• Posterior maxillary lesions may require more aggressive treatment
• Recurrence rate 15%
• Good prognosis

23

Tumors of Odontogenic
Ectomesenchyme

• Odontogenic Fibroma (central)
• Granular Cell Odontogenic Tumor
• Odontogenic Myxoma
• Cementoblastoma

24

Odontogenic Fibroma

• Histology may look the same as a hyperplastic dental
follicle – correlation with clinical and radiographic
presentations necessary

25

Odontogenic fibroma locations

• 45% maxillary, mostly anterior to the first premolar
• 55% mandible, half of which are posterior to the first
molar

26

Odontogenic fibroma gender predilection and avg age

• Wide age range, mean age 40 years
• F>M, app 2:1

27

Clinical and radiographic presentation of Odontogenic Fibroma

• Clinical notch or depression in the palate is characteristic of maxillary
OF’s
• Small lesions appear unilocular; large lesions can appear multilocular
• 12% exhibit radiopaque flecks
• Root resorption is common; also root divergence
• Two accepted histologic presentations: simple type and WHO type

28

Odontogenic fibroma tx and prognosis

• Enucleation and vigorous curettage
• Recurrences uncommon, prognosis good

29

Odontogenic Myxoma age, location and gender facts

• Commonly young adults, average age 25-30 years, no
gender predilection
• Any location within jaws, mandible more common

30

Odontogenic Myxoma Radiographic appearance

• Radiographic: Uni- or multilocular radiolucency,
irregular or scalloped margins
• Thin trabeculae of bone arranged at right angles
• May exhibit a soap bubble pattern

31

Odontogenic Myxoma – Treatment and Prognosis

• Small lesions may be treated with curettage, but follow-up is
necessary
• Larger lesions may need resection due to infiltration of surrounding
bone
• Recurrence near 25%
• Overall good prognosis, no reported metastases
• Rare myxosarcoma: cellular atypia and more aggressive; No
metastasis

32

Cementoblastoma

• Age: Young adults; <25
yrs
• Sex: No predilection (M?)
• Site: 75% in mandible, 1st
molar
• Radiographic:
Pathognomonic –
attached to a tooth root
• Clinical: May be painful
and expansile
• Completely excise

33

Mixed Odontogenic Tumors

• Composed of ectomesenchymal and odontogenic epithelial elements
• Compound and complex odontomas
• Ameloblastic fibroma
• Ameloblastic fibro-odontoma
• Ameloblastic fibrosarcoma

34

Odontoma

Hamartoma (developmental anomaly)
• Compound – multiple small structures resembling teeth; most common
• Complex – conglomeration of enamel and dentin
• Mean age is 14 years
• More common in the maxilla
• Usually asymptomatic, associated with failure of tooth eruption

35

Odontoma Radiographic presentation

Radiographically exhibits radiodensity similar to teeth,
surrounded by a narrow radiolucent rim

36

Odontoma Tx

Local excision, excellent prognosis

37

Ameloblastic Fibroma

• Both the epithelial and mesenchymal tissues are neoplastic
• Most often diagnosed within first two decades of life; males slightly
outnumber females
• 70% posterior mandible; may grow large
• Radiographically, unilocular or multilocular radiolucency, welldefined,
possibly sclerotic border
• 75% associated with unerupted tooth

38

Ameloblastic Fibroma – Treatment and Prognosis

• Initial lesions are treated conservatively, with local excision or
curettage
• Recurrent lesions are treated with more aggressive surgical resection
• Recurrence rates reported from 0 to 45% after conservative removal

39

Ameloblastic Fibro-Odontoma

• Similar to ameloblastic fibroma, but contains enamel and dentin
• Average age of diagnosis is 10 years (younger than ameloblastic
fibroma)

40

Ameloblastic Fibro-Odontoma Radiographically

Radiographically contains variable amounts of calcified material as small
radiopacities or large comglomerations; often associated with an unerupted
tooth

41

Ameloblastic fibro odontoma

Treatment consists of conservative curettage, shells out easily;
recurrence is rare, prognosis is excellent

42

Ameloblastic Fibrosarcoma

• Malignant counterpart of ameloblastic fibroma
• Mesenchymal tissue is malignant
• 45% of cases arise from a recurrence of ameloblastic fibroma or
ameloblastic fibro-odontoma
• 1.5 times as common in males, average age 27 years
• 80% occur in the mandible, exhibiting pain, swelling, and rapid
growth

43

Ameloblastic Fibrosarcoma
Radiographically

ill-defined radiolucency, destructive

44

Ameloblastic Fibrosarcoma
Treatment

Radical surgery is
recommended
• Death usually occurs
due to uncontrolled,
aggressive local disease