Odontogenic Cysts Flashcards
What is the definition of an odontogenic cyst? What do they arise from?
Pathologic cavity lined by odontogenic epithelium and filled with fluid of semisolid material
Arise from the rests of the dental lamina (Serres and Malassez)
What are the top 4 odontogenic cysts?
Dentigerous cyst
Odontogenic Keratocyst
Orthokeratinized Odontogenic Cyst
Calcifying Odontogenic Cyst
What are the top odontogenic tumors based of epithelial and mixed origin?
Epithelial origin = Adenomatoid Odontogenic Tumor, Calcifying Epithelial Odontogenic Tumor
Mixed origin= Ameloblastic Fibroma, Ameloblastic Fibro-odontoma, Odontoma
What is the most common development cyst? What does it originate from?
Dentigerous cyst
Originates by separation of the follicle from around the crown of an unerupted tooth
Where are dentigerous cysts attached at on the unerupted tooth?
The CEJ
What teeth are most commonly involved in a dentigerous cyst?
The mandibular 3rd molars
Followed by Maxillary 3rds, then Maxillary canines
Almost never occur in deciduous teeth
What term describes a cyst filled with keratin (cottage cheese like) debris?
Odontogenic keratocyst
What are the 2 most important things to remember about odontogenic keratocysts?
30% recurrence rate and Associated with Gorlin’s syndrome
What is another name for Gorlin’s syndrome? What is Gorlin’s syndrome? What is it caused by?
Nevoid basal cell carcinoma syndrome
Characterized by multiple Basal cell carcinomas, OKCs, calcification of the falx cerebri, rib anomalies
Caused by abnormality in PTCH gener on Chromosome 9
Why do so many Odontogenic Keratocysts recur?
OKCs have thin, friable walls so complete removal is often difficult
What are the histopathologic features of odontogenic keratocysts?
Thin, friable wall
Wavy, parakeratinized epithelial lining that is a uniform 6-8 layers thick
Palisading, hyperchromatic basal cell layer (like a picket fence)
Daughter cysts
What do odontogenic keratocysts radiographically appear as?
Radiolucent lesions with corticated rims
Large lesions can be multilocular
1/3 are associated with an unerupted tooth
What makes orthokeratnized odontogenic cysts different than odontogenic keratocysts?
Orthokeratinized odontogenic cysts have an orthokeratinized lining and no basal palisading
Why is the term traumatic bone cyst a misnomer?
Because the lesion does not have an epithelial lining
What is the current theory of the etiology of traumatic bone cysts?
Trauma-hemorrhage theory = trauma to the bone which causes a hematoma, but hte hematoma does not undergo organization and repair, resulting in a defect
In what age population are traumatic bone cysts in the jaw most commonly found? Where are they found?
In patients between 10-20, and they exclusively occur in the mandible
There may be swelling, but usually asymptomatic
What term describes a unilocular, well defined RL with RO structures usually found in the incisor canine area? What age are most patients with this lesion?
Calcifying odontogenic cyst
35
What is another name for calcifying odontogenic cyst?
Gorlin cyst
What term describes a unilocular, well defined RL lesion in the anterior maxilla with snowflake calcifications? What age are most patients with this lesion?
Adenomatoid odontogenic tumor
Between ages 10-20, and more often female
Asymptomatic, around a tooth that has not erupted
What term describes a unilocular/multilocular, with well defined scalloped margins and calcifications in a driven snow pattern? What are the histopathologic features of this lesion?
Calcifying Epithelial Odonotgenic Tumor
Nuclear pleomorphism and atypia
Amyloid like ECM - stains congo red, and has an apple green birefringence when viewed under polarized light
Calcifications form concentric rings in amyloid like areas (liesegang rings)
What is another name for calcifying epithelial odontogenic tumor?
Pindborg tumor
What is the most common odontogenic tumor? Is it a true neoplasm?
Odontoma
Not a true neoplasm, considered a hamartoma
What are the two types of odontomas and what are the differences between these types?
Compound and Complex
Compound = composed of multiple, small tooth like structures
Complex = conglomerate mass of enamel and dentin
What is the average age of patients with odontomas? What are they associated with? What type is more common?
15
Unerupted tooth
Compound more common in anterior, complex more common in molar regions
What term describes a true mixed tumor with islands of dental papilla like tissue and ameloblasts? What is the average age of patients with this lesion and where do they occur?
Ameloblastic fibroma
Occur in younger patients, before age 20
Located in the posterior mandible
What term describes a lesion that is a true mixed tumor and has enamel and dentin? What is the average age of patients with this lesion and where do they occur?
Ameloblastic Fibro-Odontoma
Average age is 10
Occurs in the posterior jaws
What is the most common clinically significant odontogenic tumor? (not on ppt)
Ameloblastoma
What are the 3 different types of ameloblastomas?
not on ppt
Convention solid/multicystic
Unicystic
Peripheral
What is the clinical presentation of ameloblastomas?
not on ppt
Painless swelling posterior mandible (except desmoplastic which is anterior maxilla)
What is the radiographic presentation of ameloblastomas?
not on ppt
Mulitlocular RL that is either soap bubble or honeycombed in appearance
Buccal and lingual cortical expansion is frequently present
What are the histopathologic features of ameloblastomas?
not on ppt
Palisading, hyperchromatic basal layer
Reverse polarity
Apical vacuolization
What is the difference between malignant ameloblastoma and metastatic ameloblastoma?
(not on ppt)
Malignant is cancer, metastatic is benign but is somewhere it shouldn’t be – once the patient gets the matastatic removed they will be fine and have no worries
