Odontogenic Cysts and Tumors Flashcards
what is the definiteion of an odontogenic cyst?
a pathologic cavity lined by odontogenic epithelium and filled with fluid or semisolid fluid
which odontogenic tumors are odontogenic epithelial in origin?
- adenomatoid odontogenic tumor (AOT)
- calcifying epithelial odontogenic tumor (CEOT)
what are 3 mixed odontogenic tumors?
- ameloblastic fibroma
- ameloblastic fibro-odontoma
- odontoma
___ is a cyst that originates by separation of the follicle from around the crown of an unerupted tooth
dentigerous cyst
what is the most common developmental cyst?
dentigerous cyst
a dentigerous cyst encloses the ___ of an unerupted tooth and is attached at the ___
- crown
- CEJ
dentigerous cyst
dentigerous cyst
dentigerous cyst
dentigerous cyst
dentigerous cysts involve which teeth most commonly?
man 3rds > max 3rds > max canines > man canines
do dentigerous cysts cause expansion?
not usually, unless they are left untreated long enough
the white stuff is keratin
can be either an orthokeratinized odontogenic cyst or odontogenic keratocyst
what are the two most important things to know about odontogenic keratocysts?
- 30% recurrence rate
- assocaited with Gorlin’s syndrome
Gorlin’s syndrome is also called ___
nevoid basal cell carcinoma syndrome
what chromosome and gene is associated with gorlin’s syndrome?
chromosome 9, PTCH gene
odontogenic keratocyst
odontogenic keratocyst
odontogenic keratocyst
describe the histological appearance of an odontogenic keratocyst
- thin, friable wall
- epithelial lining is a uniform 6-8 cell layers thick
- basal cell layer shows palisading and is hyperchromatic
- epithelium is surfaced by wavy parakeratin
- may have small satellite cysts away from the primary lesion (“daughter cysts”)
what is one of the main reasons the recurrence rate of OKCs is so high?
daughter cysts
OKC
OKC
OKC
___ is an odontogenic cyst with orthokeratinized lining and no basal palisading
orthokeratinized odontogenic cyst
what location are OOCs most common?
posterior mandible
what is the radiographic presentation of an OOC?
- typically unilocular
- usually appears as a dentigerous cyst around a 3rd molar
what is the recurrence rate of an OOC?
2% after enucleation with curettage
technically this is an OOC (presents as a dentigerous cyst around a 3rd molar), but you’d need a biopsy to confirm
which one is an OOC and which is the OKC?
OOC on the left, OKC on the right
empty cavity
traumatic bone cyst
traumatic bone cyst
traumatic bone cyst is also called a ___
simple bone cyst
___ is a benign, empty, or fluid filled cavity within bone
traumatic bone cyst
do traumatic bone cysts have an epithelial lining?
no, so “cyst” is actually a misnomer
what is the most widely accepted etiological theory for tramatic bone cysts?
- trauma-hemorrhage theory
- trauma to the bone is insufficient to cause a fracture so it results in an intraosseous hematoma
- if the hematoma does not undergo organization and repair, it may liquefy and result in a defect
what age range are traumatic bone cysts typically found? what is the most common location?
10-20, almost exclusively in the mandible
how do traumatic bone cysts present clinically?
asymptomatic, 20% have a swelling
asymptomatic, empty cavity
traumatic bone cyst
asymptomatic, empty cavity
traumatic bone cyst
calcifying odontogenic cyst
ghost cells
calcifying odontogenic cyst
what is another name for a calcifying odontogenic cyst?
gorlin cyst
what is the most common location for calcifying odontogenic cysts?
65% are found in the incisor/canine area
mx=md
20% of calcifying odontogenic cysts are associated with ___
odontomas
what are the radiographic features of calcifying odontogenic cysts?
- unilocular, well-defined RL
- RO structures are seen within the RL in 50%
- 1/3 are associated with an unerupted tooth (usually canine)
calcifying odontogenic cyst
- 10-year old female
- parents brought her in for failure of her tooth to erupt
adenomatoid odontogenic tumor
notice the snowflake calculations
what age range do adenomatoid odontogenic tumors occur in?
10-20
AOTs have a tendency to occur in what location?
anterior jaws
more common in the maxilla and in females
how are AOTs typically discovered?
they are asymptomatic and typically discovered radiographically to determine why a tooth hasn’t erupted
how do AOTs present radiographically?
- in 75% of cases, the tumor is a circumscribed, unilocular RL involving the crown of an unerupted tooth (most often a canine)
- RL often extends apically past the CEJ
- lesions may contain snowflake calcifications
how can AOTs be distinguished radiographically from dentigerous cysts?
the RL often extends past the CEJ in AOTs, as opposed to stopping at the CEJ in dentigerous cysts
adenomatoid odontogenic tumor
notice it is around an unerupted canine
adenomatoid odontogenic tumor
calcifying epithelial odontogenic tumor
calcifying epithelial odontogenic tumor is also called a ___
pindborg tumor
what is the most common location for a CEOT?
posterior mandible
what is the most common presenting sign of a CEOT?
painless, slow-growing swelling
what is the radiographic presentation of a CEOT?
- can be unilocular or multilocular
- unilocular is more common in the maxilla
- margins are typically scalloped and well-defined, may be corticated or ill-defined
- frequently associated with an impacted tooth (most often a mandibular molar)
- contains calcified structures of varying size and density
- some believe the clacifications are prominent around the crown in a “driven-snow” pattern (occurs in 10%)
what are the histopathologic features of a CEOT?
- nuclear pleophorphism and atypia
- amyloid-like extracellular material, positive for congo red, which exhibits an apple-green birefringence when viewed under polarized light
- calcifications with concentric rings form in the amyloid-like areas (liesegang rings)
calcifying epithelial odontogenic tumor
the purple represents calficicaitons, and the light pink are the amorphous amyloid-like areas
CEOT
the gray represents liesegang rings, and the white arrows point to cells exhibiting nuclear atypica and pleomorphism
CEOT
positive for congo red
compound odontoma
what is the most common odontogenic tumor?
odontoma
are odontomas true neoplasms?
no, they are considered to be developmental anolalies (hamartomas)
what are the two types of odontomas? how do they differ from each other?
- compound - multiple, small, toothlike structures
- complex - conglomerate mass of enamel and dentin; bears no anatomic resemblance of a tooth
what is the average age patient with an odontoma?
15
odontomas are usually associated with a ___
unerupted tooth
compound odontomas are more common in what location? what about complex odontomas?
- compound - anterior maxilla
- complex - molar regions
compound odontoma
complex odontoma
ameloblastic fibromas are true mixed tumors, consisting of both ___ and ___ tissues
epithelial and mesenchymal tissues
ameloblastic fibromas occur in what age patient?
younger, usually before age 20
70% of ameloblastic fibromas are located in the ___, and 75% are associated with a ___
posterior mandible, unerupted tooth
ameloblastic fibroma
ameloblastic fibroma
ameloblastic fibroma
ameloblastic fibroma
ameloblastic fibro-odontomas histologically appear similar to ameloblastic fibromas, except they also have ___
enamel and dentin
what is the average age patient with an ameloblastic fibro-odontoma?
10
ameloblastic fibro-odontomas typically occur in what location?
posterior jaws
what is the radiographic presentation of an ameloblastic fibro-odontoma?
- well-circumscribed unilocular radiolucency
- contains varying amounts of calcified material
- typically associated with an unerupted tooth
what is the treatment for ameloblastic fibro-odontoma?
conservative curettage with rare recurrence
ameloblastic fibro-odontoma
