Oral pathology - Common Findings

Question 1

What are the 2 types of inflammatory odontogenic cyst?

Answer 1

1. Radicular cyst
2. Inflammatory Collateral cysts

Question 2

What are the 3 types of radicular cyst?

Answer 2

Apical
Lateral
Residual

Question 3

Where does a lateral radicular cyst arise from?

Answer 3

A lateral root canal branch of a non-vital tooth

Question 4

Where does a residual radicular cyst arise from?

Answer 4

Persists after an extraction of the associated non-vital tooth

Question 5

Name the most common type of jaw cyst?

Answer 5

Radicular cyst

Question 6

What % of odontogenic cysts are radicular cysts?

Answer 6

55%

Question 7

What do radicular cysts arise from?

Answer 7

Epithelial proliferation and cystic formation within some periapical granuloma

Question 8

Where are radicular cysts most commonly found?

Answer 8

Anterior maxilla

Question 9

Are radicular cysts rapid or slow growing swellings?

Answer 9

Slow growing swelling

Question 10

Would you expect symptoms with a radicular cyst?

Answer 10

Often no symptoms, unless very large

Question 11

What are radicular cysts associated with?

Answer 11

Non-vital tooth - usually at the apex, although can be on lateral aspect of root if associated with lateral canal.

Question 12

How would you describe the radiographic appearance of a radicular cyst?

Answer 12

Typically well-circumscribed unilocular radiolucent lesion seen at the apex.
(although can be on the lateral aspect of the root if associated with a lateral canal)

Question 13

What is the pathogenesis associated with radicular cysts?

Answer 13

The proliferation of epithelium (Cell Rests of Malassez) in response to inflammation
Cyst enlarges due to osmotic pressure
Local bone resorption

Question 14

What does the presence of hyaline/rushton bodies in the histopathological study of a cystic lesion indicate?

Answer 14

That the cystic lesion is of odontogenic origin

Question 15

What are hyaline/rushton bodies secreted by?

Answer 15

The cyst lining

Question 16

What is the treatment for radicular cysts?

Answer 16

Small cysts may resolve after RCT/extraction/periradicular surgery
Larger lesions may require enucleation (entire removal of the lesion)
Very large lesions may require marsupilisation (decompression) before enucleation

Question 17

What causes the formation of inflammatory collateral cysts?

Answer 17

Inflammation associated with pericoronitis.
Proliferation of sulcular or junctional epithelium derived from reduced enamel epithelium.

Question 18

What are the 2 types of inflammatory collateral cyst?

Answer 18

Paradental cyst
Mandibular buccal bifurcation cyst

Question 19

Which teeth are paradental cysts commonly associated with?

Answer 19

Lower 3rd molars

Question 20

What % of inflammatory collateral cysts are paradental cysts?

Answer 20

> 60%

Question 21

Are paradental cysts associated with a vital or non-vital tooth?

Answer 21

A vital tooth - they are associated with chronic pericoronitis

Question 22

How do inflammatory odontogenic cysts (paradental cyst and mandibular buccal bifurcation cyst) appear radiographically?

Answer 22

Well demarcated radiolucency

(Mandibular bifurcation cyst is seen buccally)

Question 23

Which teeth are mandibular buccal bifurcation cysts commonly associated with?

Answer 23

Lower 1st and 2nd molars - associated tooth usually tilted buccally with deep perio pocket

Question 24

Would you expect symptoms associated with a mandibular buccal bifurcation cyst?

Answer 24

No - often painless swelling

Question 25

How are inflammatory odontogenic cysts treated?

Answer 25

Mandibular buccal bifurcation cysts - enucleation Paradental cysts - removal of 8s and paradental cyst

Question 26

Name 7 developmental odontogenic cysts:

Answer 26

1. Odontogenic Keratocyst 2. Dentigerous cyst/Eruption cyst 3. Lateral periodontal cyst and Botryoid odontogenic cyst 4. Glandular odontogenic cyst 5. Gingival cysts 6. Calcifying odontogenic cyst 7. Orthokeratinised odontogenic cyst

Question 27

Where does an OKC arise from?

Answer 27

Glands of Serres

Question 28

What % of OKCs arise in the mandible?

Answer 28

80% - especially posteriorly

Question 29

Would you expect symptoms associated with an OKC?

Answer 29

Symptomless unless infected or when cortical bony expansion is evident

Question 30

Which direction does cortical bony expansion occur in OKCs?

Answer 30

In an anterior-posterior direction

Question 31

How do OKCs appear radiographically?

Answer 31

Well-defined radiolucent uni- or multi-locular lesion

Question 32

OKCs are associated with the mutation or inactivation of which gene?

Answer 32

PTCH1 gene (found in chromosome 9)

Question 33

Which syndrome can be associated with OKCs?

Answer 33

Naevoid Basal Cell Carcinoma Syndrome (Gorlin Syndrome)

Question 34

How do OKCs present in patients with Naevoid Basal Cell Carcinoma Syndrome?

Answer 34

Multiple (recurring) Odontogenic Keratocysts

Question 35

What happens to the characteristic histopathological features of OKCs if secondary infection is present?

Answer 35

The histopathological features are lost

Question 36

Why do OKCs have a high recurrence rate on removal?

Answer 36

Due to thin capsule/daughter cysts

Question 37

Which ways might OKCs be treated?

Answer 37

Marsupilisation Enucleation Marsupilisation and Enucleation Enucleation and Carnoy's Enucleation and Cryotherapy Resection

Question 38

Which solution can be used to aid elimination of remaining daughter cysts following enucleation of OKC?

Answer 38

Carnoys solution

Question 39

What is the % recurrence rate following the removal of an OKC using enucleation and Carnoys solution?

Answer 39

<10% recurrence rate

Question 40

What is a dentigerous cyst?

Answer 40

2nd most common odontogenic cyst An accumulation of fluid between the reduced enamel epithelium of the dental follicle and the crown of an un-erupted tooth.

Question 41

Which teeth are associated with dentigerous cysts?

Answer 41

Impacted teeth or late to erupt (3s, 5s, 8s)

Question 42

Are dentigerous cysts most commonly seen in the mandible or the maxilla?

Answer 42

Mandible

Question 43

Would you expect symptoms associated with a dentigerous cyst?

Answer 43

No unless significant swelling present or infected

Question 44

How might a dentigerous cyst appear radiographically?

Answer 44

Well-circumscribed unilocular radiolucency associated with the crown of un-erupted tooth

Question 45

What type of expansion is associated with a dentigerous cyst?

Answer 45

Ballooning expansion

Question 46

Where are dentigerous cysts clinically attached to on the UE tooth?

Answer 46

The ACJ

Question 47

How would you treat a dentigerous cyst?

Answer 47

Enucleation with exposure/transplantation/extraction of associated tooth

Question 48

Which type of dentigerous cyst arises in an extra-alveolar location?

Answer 48

Eruption cyst

Question 49

How does an eruption cyst present clinically?

Answer 49

Bluish swelling in primary and permanent molars

Question 50

How are eruption cysts treated?

Answer 50

Nothing - should erupt naturally Exposure of erupting tooth

Question 51

Name the 2 most common odontogenic tumours:

Answer 51

1. Odontoma 2. Ameloblastoma

Question 52

What are odontomas?

Answer 52

Developmental malformations (hamartomas) of dental tissues

Question 53

What are the 2 different types of Odontomas?

Answer 53

Compound type (most common) Complex type

Question 54

Where are compound-type Odontomas frequently found?

Answer 54

In the anterior maxilla

Question 55

What do compound type odontomas look like?

Answer 55

A bag of teeth

Question 56

Where are complex-type Odontomas frequently found?

Answer 56

Posterior mandible

Question 57

What do complex type odontomas look like?

Answer 57

Irregular mass of hard and soft dental tissues, haphazard arrangement with no resemblance to a tooth and often forming a cauliflower-like mass

Question 58

How do you treat odontomas?

Answer 58

Enucleation

Question 59

Where are conventional ameloblastomas frequently found?

Answer 59

Posterior mandible

Question 60

Name 2 features of ameloblastoma?

Answer 60

Slow growing Locally aggressive

Question 61

What are the 2 patterns of ameloblastoma in fibrous tissue stroma?

Answer 61

1. Follicular pattern - islands of epithelial cells 2. Plexiform pattern - long strands of epithelial cells

Question 62

What is important to note about maxillary located ameloblastomas?

Answer 62

They are rare however, they are readily spread through thin bones of the base of the skull, are difficult to completely excise and are potentially LETHAL.

Question 63

Which drugs commonly result in lichenoid reactions?

Answer 63

Antihypertensives - ACE inhibitors, beta-blockers, calcium channel blockers, methyldopa, thiazide, diuretics, loop diuretics (e.g. frusemide) Oral hypoglycaemics - Tolbutamide, Chlorpropamide (sulphonylureas) NSAIDS - ibuprofen, naproxen, phenylbutazone

Question 64

What histopathological features can be seen in lichenoid inflammation?

Answer 64

Hyperorthokeratosis and hyperparakeratosis of the epithelium - may be acanthotic Saw tooth rete ridges Lymphocytic exocytosis Civatte bodies (basal cells undergoing apoptosis) Breakdown of basal cell layer

Question 65

If symptomatic, how might you treat lichenoid inflammation?

Answer 65

Steroid treatment

Question 66

What % of parotid tumours are pleomorphic adenoma?

Answer 66

60%

Question 67

What are pleomorphic adenomas?

Answer 67

Most common type of salivary gland tumour. Benign, typically but not always painless, slow growing, rubbery lump.

Question 68

Are pleomorphic adenomas solitary or multifocal?

Answer 68

Usually solitary, however recurrences may be multifocal

Question 69

Most pleomorphic adenomas are associated with gene rearrangements in ….

Answer 69

PLAG1 or HMGA2

Question 70

What histopathological features can be seen in pleomorphic adenoma

Answer 70

Well circumscribed tumour Incomplete fibrous capsule May be cystic Complex intermingling of epithelial and myoepithelial components

Question 71

What is the treatment for pleomorphic adenoma?

Answer 71

Complete excision High recurrence rate if incompletely excised Malignant transformation can occur - usually in long standing lesions

Question 72

What are malignantly transformed pleomorphic adenomas known as?

Answer 72

Carcinoma ex pleomorphic adenoma

Question 73

What is the prognosis of carcinoma ex pleomorphic adenoma?

Answer 73

Typically high grade malignancies with poor prognosis