Bone lesions and cysts - radiology and histology Flashcards Preview

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Flashcards in Bone lesions and cysts - radiology and histology Deck (78)
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1

How to describe a lesion on an x-ray (6)

Site
Size
Shape
margins
radio density
effects on surrounding structures

2

What is the definition of a cyst
[3]

Pathological cavity filled w fluid, semi-fluid or gaseous contents.
Not filled with pus.
Has a wall, a lining (epithelium) and a lumen.

3

3 things/steps needed for a cyst to form

1. A source of epithelium
2. A stimulus for proliferation
3. Growth and bony resorption

4

Types of cysts in the jaws
[10]

Odontogenic cysts:
developmental (dentigerous cyst, eruption cyst, lateral periodontal cyst or odontogenic keratocyst)
Inflammatory (radicular cyst apical or lateral, residual cyst, paradental/collateral cyst)
Non-odontogenic cysts:
nasopalatal cyst
nasolabial cyst

5

How do cysts grow and proliferate
[7]

Breakdown in the centre of the cyst. This brings water into the cyst via osmosis which increases the hydrostatic pressure and makes the cyst grow + proliferation of the epithelium. Process continues.
Interleukin, cytokines drive this and activate Oc and cause bone resorption.

6

Radicular cyst epithelium source

Hertwigs root sheath/epithelial rests of Malassez in the PDL.

7

Stimulus for the formation of a radicular cyst
[3]

Chronic periapical inflammation/periapical periodontitis is replaced with granulation tissue to make a periapical granuloma.

8

location of radicular cyst
[2]

always associated w a non-vital tooth. Can be apical or lateral (lateral canals) or residual.

9

radiographic appearance of radicular cyst
[5]

well defined, corticated, large (15mm) radiolucency, continuous with the PDL

10

histological appearance of radicular cyst
[2]

non-keratinised epithelial lining, lots of chronic inflammatory cells.

11

how is a collateral/paradental cyst formed
[4]

stimulus is periodontal pocket inflammation and the cyst forms on the lateral aspect of the tooth.
Epithelium arises from the pocket epithelium.
Tooth needs to be at least partially erupted

12

histology of paradental cyst
[2]

attached at the ACJ and looks like a radicular cyst.

13

follicular cyst formation
[4]

cyst surrounding the crown of an unerupted tooth.
A developmental cyst
arises from the reduced enamel follicular epithelium.
Normal radiolucency around a developing tooth crown is 3mm (between the crown and the follicle)

14

dentigerous cysts + radiographic and histological features
[3]
[3]

Impacted tooth still in bone.
Well-defined, corticated radiolucency surrounding the crown and attaching at the ACJ.
Histologically = minimal inflammation, thin and regular non-keratinised epithelium

15

eruption cyst
[3]

a cyst surrounding the crown of an erupting tooth that is not in the bone.
Can impede the eruption of the tooth

16

how is an odontogenic keratocyst formed
[3]

arises from the dental lamina remnants.
Can be associated with an unerupted tooth, and in the 3rd molar region a lot of the time bc that's where you find remnants of dental lamina.

17

odontogenic keratocyst clinical/histological/ radiographic appearance
[2]
[6]
[2]

aggressive and infiltrative growth.
Fragile lining (thin parakeratinised, with the basal layer nuclei all standing in a line (nuclear palisading)). Fragile lining means bits get broken off when removal is attempted so has a high recurrence rate.
Can get daughter cysts which bud off and are easy to leave behind.
Cyst can be solid (filled w keratin if small).
radiographic = multi or unilocular, w smooth or irregular outlines and not much bucco-lingal expansion even if very large.

18

Odontogenic keratocyst associated syndrome

basal cell naevus/Gorlin-Goltz syndrome

19

what is gorlin-goltz syndrome
[6]

multiple, recurrent odontogenic keratocysts
multiple and recurrent basal cell carcinomas of skin not exposed to sun.
frontal bossing/wide forehead
calcified falx cerebri (midline in skull so transmits electrical signals more so more likely to get epilepsy)
wide set eyes
bifurcation in ribs

20

lateral periodontal cyst formation
[3]

developmental.
Forms on the lateral aspect between vital teeth.
Epithelium arises from rests of Serres..

21

radiographic appearance of a lateral periodontal cyst
[4]

multilocular, well defined, corticated radiolucency.
Has localized thickenings of the lining (called plaques)

22

gingival cysts
[4]

can be in adults and in children.

In children:
- parakeratinised epithelium
- arises from dental lamina rests in the alveolar mucosa
- located under the alveolar mucosa

In adults:
- non-keratinised epithelium
- arises from dental lamina rests in the attached gingiva
- form in the attached gingivae

23

glandular odontogenic cysts
[5]

have cuboidal or columnar epithelium w mucus production, duct like/glandular structures.
High recurrence rate

24

calcifying odontogenic cyst
[5]

in young children.
radiolucency w calcification's.
lined with ameloblastoma-like epithelium and has ghost cells and dentine.

25

non-odontogenic cysts

nasopalatine cyst and nasolabial cysts

26

nasopalatine cyst formation
[2]

midline of anterior part of palate.
from nasopalatine duct epithelial residues as the processes fuse in utero.

27

nasopalatine cyst histological /clinical/radiographic appearance
[4]
[1]
[2]

lined by respiratory or mucosal epithelium or both.
can have nerve bundles or vascular signs in the lumen.
seen as a swelling in the hard palate.
radiographically it overlies the upper central incisors roots but is separate to them i.e. doesn't interfere or resorb them.

28

nasolabial cysts location
[3]

soft tissues of face - next to the nose, base of nostril or nasolabial fold

29

nasolabial cyst epithelium
[2]

remnants of nasolacrimal duct = pseudo-stratified columnar epithelium

30

what is an odontogenic tumour
[2]

tumour that arises from epithelium or mesenchyme. Radiolucent lesion, sometimes with calcifications.