Oral Pathology Exam 3 Odontogenic Cysts

Front 1

How do Dentigerous (Follicular) Cysts appear radiographically?

Back 1

1. Unilocular Radiolucent area associated with the crown of an unerupted tooth
2. Well-defined and often has a sclerotic border
3. Higher rate of rooth resorption (aggressive)
4. Radiolucency should be 3-4 mm

Front 2

What should your #1 differential diagnosis be if you see an impacted tooth with a radiolucency associated with the crown of an impacted tooth?

Back 2

Dentigerous (Follicular) Cyst

Front 3

Who is most commonly affected by dentigerous cysts?

Back 3

20-30 yr White Males
Mand 3rd Molars & Max Canines

Front 4

What is the most common developmental cyst?

Back 4

Dentigerous (Follicular) Cyst

Front 5

What is a cyst that develops by separation of follicle from around the crown of an unerupted tooth?

Back 5

Dentigerous (Follicular) Cyst

Front 6

T/F
In the older classifications used in the US, the primordial cyst was considered to originate from the cystic degeneration of the enamel organ before the development of the dental hard tissue. Therefore, the primordial cyst was found in place of the tooth.

Back 6

True
Almost all Primordial cysts are Odontogenic Keratocysts (OKC), but not all OKCs are primordial cysts

Front 7

T/F
OKCs can be diagnosed using Xrays

Back 7

FALSE
OKC diagnosis is Strictly based on histopathology

Front 8

T/F
OKCs have a high reoccurence rate.

Back 8

True
Surgeons will go out of their way to make sure they eradicate the lesion completely and do a long term follow up. OKCs can reoccur 10-20 years after their initial diagnosis

Front 9

What are the pathogenic mechanisms of OKCs?

Back 9

1. High proliferation rate of epithelium - Ki-67 staining
2. Overexpression of antiapoptotic protein - Bcl-2staining
3. Overexpression of interface protein - MMPs 2&9, TGF, IL-1a, IL-6
4. Mutations in PTCH tumor suppressor gene
5. Found in basal cell carcinomas & nevoid basal cell carcinoma syndrome
6. Also mutated in syndromic odontogenic keratocysts
6.

Front 10

What is the "not quite" 2/3 rule involved with OKCs?

Back 10

2/3 10-40 yrs
2/3 Men
>2/3 Molar ramus areas of mandible (60-80%)
Grow in AP direction within the medullary cavity w/o causing bony expansion
Multiple OKCs should be tested for Gorlin syndrome

Front 11

Where do the cells of origin come from for an OKC?

Back 11

Cell rests of Dental Lamina

Front 12

How are OKCs treated and what is their prognosis?

Back 12

Enucleation and curettage
Other than a tendency for recurrence, the overall prognosis of an OKC is good

Front 13

How do OKCs appear radiographically?

Back 13

1. Well-defined radiolucent lesions w/smooth, cortigated margins
2. Unilocular or Multilocular
3. Many are associated with an unerupted tooth (but #1 differential should be dentigerous cyst)
4. May appear similar to: dentigerous, radicular (at the apex), residual, lateral periodontal or globulomaxillary cyst on radiograph

Front 14

What is the Histological appearance of OKCs?

Back 14

1. Thin, friable wall with little inflammatory infiltrate
2. Luminal surface shows flattened Parakeratotic Epithelial cells with a wavy/corrugated appearance
3. basal cell layer has palisaded layer of cuboidal to columnar cells, which are often hyper chromatic
4. <26% of OKCs have satellite (daughter) cysts

Front 15

Which of the following is a clinical feature commonly associated with the nevoid basal cell carcinoma syndrome?
a) Skeletal anomalies such as bifid rib
b) Odontogenic keratocysts
c) Mild ocular hypertelorism
d) All of the above
e) A & C only

Back 15

All of the above

Front 16

What are the Major Clinical Features of the Nevoid Basal Cell Carcinoma Syndrome (Gorlin Syndrome)?

Back 16

1. Multiple basal cell carcinomas of the skin
2. Odontogenic keratocysts
3. Epidermal cysts of the skin
4. Palmar/plantar pits
5. Calcified falx cerebri
6. Enlarged head circumference
7. Rib anomalies
8. Mild ocular hypertelorism
9. Spina bifida occulta

Front 17

How does Gorlin Syndrome (Nevoid Basal Cell Carcinoma Syndrome) relate to genetics?

Back 17

Autosomal Dominant trait with high penetrance and variable expressivity.
High degree of penetrance: if the individual has the gene for a particular entity, their probabilty of expressing the phenotype is high
Variable Expressivity: The gene can be expressed in a variety of ways

Front 18

Approximately 75% of patients that have Nevoid Basal Cell Carcinoma have multiple _______, which histologically are diagnosed as ____ that can either be at the same time or or over a span of time.

Back 18

Jaw Cysts
OKCs

Front 19

Where do most Lateral Periodontal (Botryoid Odontogenic) Cysts occur?

Back 19

2/3 occur in the Mand Canine-Premolar region
It is a cyst occuring in the lateral periodontal region
Inflammatory origin or an OKC has been excluded by clinical and histological means

Front 20

How do you rule out Lateral radicular cysts when comparing to Lateral periodontal cysts?

Back 20

Lateral periodontal cysts are usually asymptomatic and the associated tooth is Vital, thus ruling out the lateral radicular cyst

Front 21

What does Botryoid mean?

Back 21

Lateral Periodontal (Botryoid Odontogenic) Cyst
Botryoid = Cluster of Grapes

Front 22

Are Calcifying Odontogenic Cysts (COCs) true cysts?

Back 22

YES & NO
There is a large group of these that are true cysts that behave in a more indolent factor (most COCs are cystic). At the end of the spectrum is a neoplastic group that doesn't have a cystic lumen in them and they tend to behave more aggressively (these present as solid masses)

Front 23

Who is affected most by COCs?

Back 23

33 yrs
Females (Duh...COCs are not to be used on men, although this still occurs...but I digress)
Max Mand Incisor-canine regions
COCs associated w/odontomas occur in younger patients while the neoplastic variants appear to occur more frequently in older patients

Front 24

T/F
Neoplastic COCs make up a very Small amount of the total COCs

Back 24

True
86-98% of COCs are Non-neoplastic cysts

Front 25

What are the most characteristic histological features of COCs?

Back 25

Ghost Cells, which are eosinophilic epithelial cells characterized by the loss of their nuclei. (note: ghost cells may also be found in other lesions so their presence is not an absolute positive indicator of COC)

Front 26

What are different types of COCs?

Back 26

Gorlin Cyst
Dentinogenic Ghost Cell Tumor
Calcifying Cystic Odontogenic Tumor
Calcifying Ghost Cell Odontogenic Cyst

Front 27

What is the most common developmental odontogenic cyst?

Back 27

Dentigerous Cyst

Front 28

Whatt is the difference between a lateral periapical cyst and a lateral periodontal cyst from a clinical perspective?

Back 28

Vitality of the tooth
Lateral Periodontal Cyst is Vital

Front 29

What is the typical radiographic appearance of an adult gingival cyst?

Back 29

There isn't one (trick question)

Front 30

What are the cells of origin of the lateral periodontal cyst?

Back 30

Dental Lamina

Front 31

What are the features of the Nevoid Basal Cell Carcinoma Syndrom patient?

Back 31

1. Calcification of the falx cerebri
2. OKCs
3. Hypertelorism
4. Bifid rib or other rib anomalies
5. Basal cell carcinomas
6. Frontal bossing

Front 32

What is the most common clinically significant (not the most common) Odontogenic tumor?

Back 32

Ameloblastoma

Front 33

What is the big significance of an OKC?

Back 33

Reoccurrence

Front 34

Are Dentigerous cysts and Eruption cysts true cysts?

Back 34

True cysts: Dentigerous cysts, Eruption cysts

Front 35

T/F
The dentigerous cyst by far represents the most common type of pathologic radiolucency

Back 35

False

Front 36

T/F
The dentigerous cyst is the 2nd most common odontogenic cyst; the radicular cyst being the most common

Back 36

True

Front 37

T/F
Calcifying Odontogenic Cysts may have small foci of calcified material which appear as white flecks in the cystic radiolucency

Back 37

True

Front 38

T/F
Calcifying epithelial odontogenic tumors are always associated with unerupted teeth

Back 38

False

Front 39

What are the sub-classifications of Odontogenic Cysts?

Back 39

Developmental Odontogenic Cysts
Inflammatory Odontogenic Cysts

Front 40

What is the definition of a cyst?

Back 40

A cyst is a cavity (pathologic, often fluid-filled) that is lined by epithelium

Front 41

What makes a cyst an odontogenic cyst?

Back 41

Cysts lined by epithelium derived from odontogenic epithelium

Front 42

What is an uncommon Inflammatory Odontogenic Cyst that characteristically develops on the buccal aspect of the mandibular 1st molar in the bifurcation area?

Back 42

Buccal Bifurcation Cyst

Front 43

What are 3 Inflammatory cysts?

Back 43

1. Inflammatory Odontogenic Cysts
2. Periapical or radicular cysts
3. Residual cyst

Front 44

What else do Buccal Bifurcation cysts commonly present with?

Back 44

Proliferative periostitis (onion-skinned)
Pediatric patients
Inflammation spreads to the apex through the bone and produces a layering effect on the inferior border of the mandible of a new reactive bone formation

Front 45

What is this a histological slide of?

Back 45

A Primordial Cyst that is also an OKC

Front 46

Do OKCs have orthokeratin or parakeratin on their surface?

Back 46

OKCs have parakeratin (nuclei are present) epithelium on the surface

Front 47

What is significant about the cells between the epithelium and connective tissue?

Back 47

The basal cell layer is hyperchomatic and these cells are palisaded (lined up).

Front 48

What type of epithelium is on this odontogenic cyst?

Back 48

Orthokeratinized

Front 49

What is the most common odontogenic tumor?

Back 49

Odontoma (not a true neoplasm)

Front 50

What are the cells that most often give rise to the apical periodontal cysts?

Back 50

Rests of Malassez

Front 51

What do odontoblasts differentiate from?

Back 51

Mesenchymal tissue

Front 52

What does the dental papilla become?

Back 52

Pulpal tissue

Front 53

Where do the rests of malassez come from?

Back 53

Hertwig's root sheath

Front 54

The lesion at the tip of the arrow is most likely which of the following?
a) Compound odontoma
b) Complex odontoma
c) Mandibular torus
d) Idiopathic osteosclerosis
e) pellets from a gunshot wound

Back 54

Complex odontoma

Front 55

Which of the following statements is true concerning the pericoronal radiolucency shown in this projection?
a) A unicystic ameloblastoma should be considered in the differential diagnosis
b) A dentigerous cyst should head the list of differential diagnoses
c) Upon histologic examination the lesion could be an odontogenic keratocyst
d) All of the above
e) A & C

Back 55

All of the above

Front 56

Which cyst is not an odontogenic cyst?
a) Follicular
b) Primordial
c) Lateral periodontal
d) Incisive canal cyst
e) Dentigerous

Back 56

Incisive canal cyst

Front 57

Which cyst develops in place of a tooth?
a) Dentigerous cyst
b) Fissural cyst
c) Primordial cyst
d) Odontogenic keratocyst
e) Follicular cyst

Back 57

Primordial cyst

Front 58

The lateral periodontal cyst is defined by its location. In which area is the lateral periodontal cyst most commonly found?
a) Mandibular 3rd molar region
b) Maxillary tuberosity region
c) Between the maxillary premolars
d) Between the mandibular canine and first premolar
e) Between the maxillary canine and first premolar

Back 58

Between the Mandibular canine and first premolar

Front 59

Which of the following lesions is most likely to present as a multilocular radiolucency?
a) Globulomaxillary cyst
b) Odontogenic myxoma
c) Stafne bone cyst
d) Radicular cyst
e) Median palatal cyst

Back 59

Odontogenic myxoma

Front 60

Which of the following is true of the conventional solid/multicystic ameloblastoma?
a) They occur most commonly in the posterior portion of the mandible
b) They are slow growing odontogenic tumors that may cause bone expansion
c) Treatment consists of marginal resection with at least a 1 cm margin
d) All of the above
e) A & C only

Back 60

All of the above

Front 61

Which of the following is the most common odontogenic cyst of the jaws?
a) Dentigerous cyst
b) Lateral periodontal cyst
c) Primordial cyst
d) Periapical or radicular cyst
e) Keratocyst

Back 61

Dentigerous cyst

Front 62

Which of the following is a cyst found in place of a tooth?
a) Dentigerous cyst
b) Radicular cyst
c) Odontogenic keratocyst
d) Lateral periodontal cyst
e) Primordial cyst

Back 62

Primordial cyst

Front 63

Which of the following is a solitary cystlike radiolucency not necessarily contacting teeth?
a) Traumatic bone cyst
b) Primordial cyst
c) Both of the above

Back 63

Both of the above

Front 64

Which of the following are true of dentigerous cysts?
a) May cause delayed eruption of a tooth
b) May cause swelling
c) May cause facial asymmetry
d) All of the above
e) A & C

Back 64

All of the above

Front 65

T/F
Dentigerous (follicular) cysts are the second most common odontogenic cysts, after the radicular cyst and the most common developmental odontogenic cyst.

Back 65

True

Front 66

Which of the following can appear as pericoronal radiolucencies according to your textbook?
a) Ameloblastoma
b) Ameloblastic fibroma
c) Adenomatoid odontogenic tumor
d) All of the above
e) A & C

Back 66

All of the above

Front 67

Your textbook lists 7 distinct periapical radiolucent lesions that are the sequelae of pulpitis. Which of the following is Not included in this group of lesions?
a) Periapical granuloma
b) Radicular cyst
c) Abscess
d) Scar
e) Dentigerous cyst

Back 67

Dentigerous cyst

Front 68

Which of the following is the predominent age predilection for odontomas?
a) 5-20 years
b) 21-35 years
c) 50-70 years

Back 68

5-20 years

Front 69

Which of the following is true of adenomatoid odontogenic tumors (AOTs)?
a) Are more common in females
b) Site predilection is in the mandible
c) May appear as mixed radiolucent/radiopaque lesion
d) All of the above
e) A & C only

Back 69

A & C only
(maxillary canine region)