2 Odontogenic Tumors Flashcards
- broad spectrum of clinical behavior and microscopic appearance
- some are true neoplasms, others behave more like hamartomas
odontogenic tumors
Odontogenic tumors are classified according to composition and derivation (3):
- odontogenic epithelium
- odontogenic ectomesenchyme
- mixed
What are the odontogenic epithelium tumors? Ectomesenchyme? Mixed?
Epithelial
- ameloblastoma
- adenomatoid odontogenic tumor (AOT)
- calcifying epithelial odontogenic tumor (CEOT)
Ectomesenchyme
- odontogenic myxoma
- cementoblastoma
Mixed
- odontoma
- ameloblastic fibroma
- ameloblastic fibro-odontoma
2nd most common odontogenic tumor
ameloblastoma
- benign tumor, but behaves aggressively
- slow growing, locally invasive
ameloblastoma
3 types of ameloblastomas:
- solid/multicystic (majority)
- unicystic (5-22%)
- peripheral (1-10%)
many of these tumors have BRAF V600E mutation
solid/multicystic ameloblastoma
- wide age range (peak incidence in 4th-5th decades)
- M = F
- mandible (80-85%) > maxilla
- SLOW painless expansion of the jaw
ameloblastoma
common location of ameloblastoma
- mandible (80-85%) > maxilla
- especially molar and ramus area
- +/- association with an impacted tooth
can grow to huge proportions, uncontrolled tumor growth can be fatal
ameloblastoma
x-ray: radiolucency, often multilocular, may have a “soap bubble” or “honeycomb” appearance, root resorption of adjacent teeth
ameloblastoma
- combination of solid and cystic features
- several histologic patterns (most common = follicular)
ameloblastoma
Histology:
- islands of neoplastic epithelium within a fibrous CT stroma
- tall, columnar cells at the periphery
- reverse polarity of nucleus
- center of the islands resembles stellate reticulum (loosely arranged angular cells)
ameloblastoma
Tx:
- lesion is infiltrative and extends beyond the apparent radiographic margin
- conservative tx (curettage) = 60-80% recurrence
- resection (15% recurrence)–> removal of the entire lesion AND 1 cm beyond apparent radiographic margin
- long term follow-up (25 years)
ameloblastoma
follow-up time for ameloblastoma
25 years
- younger pts (2nd decade most common)
- SINGLE CYSTIC ACTIVITY
- posterior mandible is most common location
unicystic ameloblastoma
radiograph: unilocular radiolucency, often around an impacted 3rd molar (dentigerous cyst mimic)
unicystic ameloblastoma
Management is controversial/variable
- can be treated more conservatively?
- at least 30% recurrence after enucleation
- specific subtype may influence decision
unicystic ameloblastoma
- an ameloblastoma that metastasizes
- histology looks benign like the primary tumor (conventional ameloblastoma)
- usually goes to lungs
metastasizing ameloblastoma
metastasizing/malignant ameloblastoma vs ameloblastic carcinoma
Metastasizing/malignant ameloblastoma
- an ameloblastoma that metastasizes
- histology looks benign like the primary tumor (conventional ameloblastoma)
- usually goes to lungs
Ameloblastic carcinoma
- an ameloblastoma that has cytologic malignancy
- may or may not metastasize
- ill-defined radiographic margins
- aggressive
AOT
adenomatoid odontogenic tumor
2/3rds rule
AOT:
- teenagers
- females
- maxilla
*uncommon in pts older than 30
- strong predilection for anterior jaws
- 75% are associated with an impacted tooth
- can cause expansion but has limited growth potential
- not painful
AOT
most common tooth affected by AOT
canines
x-ray:
- unilocular, often pericoronal radiolucency
- may extend apically past the CEJ
- may contain fine “snowflake” calcifications
AOT
histo: thick fibrous capsule, duct-like tubular structures
AOT
tx: enucleation, unlikely to recur
AOT
CEOT
calcifying epithelial odontogenic tumor
another name for CEOT
Pindborg tumor
- relatively uncommon
- adults (age 30-50 most common)
- M = F
- posterior mandible
- +/- association with an impacted tooth
CEOT
x-ray: most are mixed RL/RO but can also be totally RL, unilocular or multilocular
CEOT
Histopathology
- epithelial cells
- tumor cells secrete a unique odontogenic amyloid protein called ODAM
- amyloid deposits calcify to form Liesegang ring calcifications (concentric, purple)
CEOT
tx: conservative local resection, 15% recurrence rate
CEOT
- mandible > maxilla
- wide age range, peak is 2-4th decades
- painless expansion is an early and consistent feature
- may displace or resorb teeth
odontogenic myxoma
X-ray:
- unilocular or multilocular radiolucency
- “soap-bubble” or honeycomb pattern
- residual trabeculae may be oriented ar right angles to one another “tennis racquet” trabeculae
odontogenic myxoma
gelatinous consistency
odontogenic myxoma
Histopathology:
- gelatinous loose, myxoid tissue
- few collagen fibrils
- haphazardly-arranged stellate cells
odontogenic myxoma
Tx:
- curettage for small lesions
- large lesions usually require resection
- lesion tends to infiltrate surrounding bone
odontogenic myxoma
prognosis: average recurrence rate is 25%
odontogenic myxoma
neoplasm of cementoblasts
cementoblastoma
- children and young adults (75% occur before age 30)
- mandible > maxilla
- molar/premolar region
cementoblastoma
50% occur at mandibular 1st molar
cementoblastoma
MC location of cementoblastoma
mandibular 1st molar (50%)
pain and expansion (2/3 of cases), pain described as similar to a toothache
cementoblastoma
X-ray:
- well-defined RO mass of cementum FUSED TO THE ROOT APEX
- no visible PDL between root and lesion
- thin RL border around the lesion
cementoblastoma
tx: surgical extraction of tooth with attached lesion, alternative is root amputation and endo
cementoblastoma
most common odontogenic tumor, prevalence exceeds all other odontogenic tumors combined
odontoma
probably a developmental anomaly (hamartoma) rather than a true neoplasm in most cases
odontoma
- kids and teens
- frequently associated with unerupted teeth
- often blocks eruption of teeth
- large lesions can cause expansion
- consists of varying amounts of dentin, enamel, cementum, and pulp
odontoma
2 type of odontomas:
compound
complex
compound vs complex odontoma (MC location? x-ray?)
Compound
- anterior maxilla is most common site
- x-ray: looks like multiple “tooth-like” structures of varying size and shape with a RL rim
Complex
- posterior jaws (mandible or maxilla)
- x-ray: irregular mass of calcified material with a RL rim
tx: conservative excision, recurrence is rare
odontoma
true mixed tumor (both the epithelial and mesenchymal tissues are neoplastic)
ameloblastic fibroma
- children and teens (80%)
- posterior mandible
- 80% associated with an unerupted tooth
- root resorption, jaw expansion
ameloblastic fibroma
x-ray: unilocular or multilocular radiolucency, well-defined border
ameloblastic fibroma
tx: complete excision, variable % recurrence
ameloblastic fibroma
recurrent lesions get more aggressive tx (malignant transformation to ameloblastic fibrosarcoma is possible)
ameloblastic fibroma
Histo:
- background of tissue that resembles dental papilla
- islands of odontogenic epithelium resembling those of ameloblastoma
- no production of hard tissue
ameloblastic fibroma
ameloblastic fibro-odontoma compared to ameloblastic fibroma
ameloblastic fibro-odontoma is very similar to ameloblastic fibroma, but the tumor also produces enamel and dentin
- children (average age = 10)
- posterior jaws, mandible > maxilla
- often associated with an unerupted tooth
ameloblastic fibro-odontoma
x-ray: well-defined radiolucency, usually unilocular, contains a variable amount of calcifications within
ameloblastic fibro-odontoma
tx: conservative excision, recurrence is uncommon
ameloblastic fibro-odontoma
