Cysts Flashcards
What is a cyst?
Pathological cavity containing fluid, semi-fluid or gas
-> not created by accumulation of pus
What are the inflammatory types of odontogenic cyst?
Radicular
-> residual (subtype)
Collateral
-> Paradental
-> buccal bifurcation
What are the developmental types of odontogenic cysts?
Dentigerous
-> eruption
OK
Lateral periodontal
Gingival
Glandular odontogenic
Calcifying odontogenic
Orthokeratinised odontogenic
What are the non-odontogenic epithelial cysts?
Nasolabial
Nasopalatine
Globulomaxillary
Median
What are the non-epithelial odontogenic cysts?
Solitary bone cyst
Aneurysmal bone cyst
** Stafne’s idiopathic bone cavity
What are the features of Radicular cysts?
Associated with non-vital tooth
-> follow on from apical periodontitis due to necrosis of pulp
Can be apical, lateral or residual
May expand bone and cause discharge
Ofren in lateral incisor region
60% maxilla
What is the origin of radicular cysts?
Rests of mallassez
-> from HERS (dental follicle)
What are residual cysts?
Radicular cysts remaining in jaws following extraction
How are radicular cysts treated?
Enucleation
Removal of associated tooth
When do radicular cysts tend to present?
4th-5th decades
How do radicular cysts appear radiographically?
Round or ovoid radiolucency at root apex
Unilocular
Well defined
Uniform
How do radicular cysts appear histologically?
Regular lining- NK squamous epithelium
Cholesterol depsits
Vascular capsule
Presence of inflammatory infiltrate
What are the contents of a radicular cyst?
Watery straw coloured fluid
Semi-solid brown material
Where do inflammatory collateral cysts tend to occur?
buccal aspect of partially erupted vital tooth
What teeth are paradental cysts usually associated with?
Partially erupted 8s
-> inflammatory stimulus is pericoronitis
Where do mandibular bifurcation cysts occur?
In children on buccal aspect of erupting FPM
How does a paradental cyst appear radiographically?
Well defined radiolucency related to neck and coronal third of root
-> similar to radicular
What are the features of a dnetigerous cyst?
Most common of this type
Associated with impacted 8s
M>F
2nd-3rd decades
Incidental finding- asymptomatic
Where do denitgerous cysts arise from?
Reduced enamel epithelium (enamel organ)
How do dentigerous cysts present radiographically?
Embrace all/part of crown of unerupted tooth- attaches at CEJ
Round/oviod radiolucency
Well-defined/uniform
Unilocular
What are the histopathological features of dentigerous cyst?
Thin regular layer of NK stratified squamous epithelium
What are the contents of a dentigerous cyst?
Proteinacous yellowish fluid
-> cholesterol crystals common
How are dentigerous cysts treated?
Enucleation with associated tooth
Marsupialisation if large
What are the features of an eruption cyst?
Overlies an erupting tooth
-> deciduous teeth/FPM
Similar histopathology to dnetigerous
Surgical excision may be required
What is the third most common odontogenic cyst?
OK
What does an OK arise from?
Rests of serres (dental lamina)
What are the issues in OKs?
High risk of recurrence
Enlarges AP- unusual pattern, can reach large size without causing bony expansion
What are the clinical features of OK?
M>F
Wide age range
70-80% occur in mandible
-> mostly in 8 region
Asymptomatic
How do OKs present radiographically?
Oval radiolucency
Well defined/uniform
Uni or multilocular
How do OKs appear histopathologically?
Thin connective tissue wall
No inflammation
Lined by thin- folded parakeratinsied stratified squamous epithelium
What is the contents of an OK?
Thick grey/white material with keratinous debris
What is Gorlin-Goltz syndrome?
Autosomal dominant syndrome
Multiple OKs
Multiple Naevoid Basal cell Carcinomas on skin
Skeletal abnormalities (abnormal Ca/PO metabolism)
-> Ribs/vertebrae affected
-> Calcified falx
What are the facial characteristics of Gorlin-Goltz?
Frontal, temporal, parietal bossing
Hypertolerism
Mild mandibular prognathism
What is an orthokeratinised odontogenic cyst how is it different from an OK?
Used to be considered variant of OK
-> similar presentation but histologically disntinct (orthokeratinisation and flattened basal cell layer)
-> unilocular without epithelial proliferations or satellite cells
-> No naevoid BCCs
-> rarely recur
What teeth are lateral periodontal cysts associated with?
Canine and premolar region in mandible
Vital teeth
-> Asymptomatic/incidental (may present with expansion)
How do lateral periodontal cysts appear radiographically?
Well demarcated radiolucent area in lateral periodontium
What are the histological features of Lateral periodontal cysts?
Thin Stratified squamous lining
Similar to gingival cyst
How are Lateral periodontal cysts treated?
Enucleation
What is a botryoid odontogenic cyst?
Multi-locular variant of LPC
Often larger
More likely to recur
What is the origin of gingival cysts?
Rests of serres (dental lamina) in gingival or alveolar soft tissues
How do gingival cysts present?
As a <1cm pink/blueish sessile swelling in the attached mandibular gingivae
What are gingival cysts in infants called, how do they present?
Bohn’s nodules
-> small yellow nodules on edentulous alveolar mucosa
-> degenerate, no tx required
What are the features of Glandular odontogenic cysts?
Rare
Potentially aggressive, locally invasive
-> can cause erosions of cortical plate
High recurrence
Uni/multilocular radiolucency
Uninflamed fibrous wall with cuboidal epithelium (glandular)
Where do glandular odontogenic cysts tend to occur?
Anterior mandible- slow growing and painless
What is a calcifying odonotogenic cyst?
Member of ghost cell family of odontgenic lesions
-> appear as ghost epithelial cells histologically
How does calcifying odontogenic cyst present clincially?
Wide age rage- usually <40
Intraosseous
Arise anterior to FPM
1-3mm in diameter
Rarely recur
Benign
What are the radiographic features of calcifying odontogenic cysts?
Initially radiolucent- then starts to contain calcified radiopaque material
Uni/multilocular
Adjacent teeth may be displaced or resorbed by bony expansion
What is the origin of nasopalatine duct cyst?
Epithelial remnants of naso-palatine duct
How do naso-palatine duct cysts present?
M>F
5-6th decades
Asymptomatic/incidental
Slowly enlarging swelling in anterior region of palate at midline
How do nasopalatine duct cysts appear radiographically?
Round, ovoid, heart-shaped radiolucency
Sclerotic margin
Well-defined
What are the histopathological characteristics of NPDC?
Lined by stratified squamous and respiratory epithelium
Neuromuscular bundles found in capsule
What is the aetiology of a solitary bone cyst?
(known as simple, haemorrhage, traumatic)
Unknown
How does a solitary bone cyst present?
Any age/sex
Premolar/molar region of mandible
Asymptomatic/incidental
Bone expansion in 25%
How do solitary bone cysts appear radiographically?
Radiolucent
Variable size
Irregular outline- scalloped
-> Moderately well defined
What occurs on surgical exploration of solitary bone cysts?
Rough bony walled cavity with no lining
-> rapid healing occurs
-> spontaeously resolves
What is stafne’s bone cavity?
Developmental anomaly of mandible
-> asymptomatic and incidental
What are the radiographic features of Stafne’s bone cavity?
Round or oval radiolucency
Occurs between premolars and angle of mandible
Located below IDC
Can be bilateral
What is found on surgical exploration of Stafne’s?
Saucer shaped depression in lingual aspect of mandible
-> contains ectopic salivary tissue
What are examples of differential diagnoses for radiolucent lesions that are non-cystic
Odontogenic tumours
-> ameloblastoma, ameloblastic fibroma, odontogenic fibroma and myxoma
Giant cell lesions
-> cherubism, peripheral/central giant cell granuloma, Brown tumour
Fibro-cemento-osseus lesions
-> Periapical cemento-osseous dysplasia, fibrous dysplasia
Non-odontogenic tumours
-> chondroma, osteosarcoma, SCC, metastatic bone tumours, central haemangioma
What are the treatment options for Cysts?
Enucleation- remove entire lining and contents
-> radicular, residual, dentigerous, kerato
Marsupialisation- create fenestration with tube or grommet
-> larger cysts
Surgical resection- removal of cyst with margin of normal bone
-> ameloblastoma/sarcoma
-> may require secondary surgery
What are the complications for enucleation?
Damage to IAN
OAC
Pathological fracture of mandible
Risk of recurrence
What are the complications of marsupialisation?
Further surgery required for removal of cyst
Long treatment
Chance of re-infection of cyst
Uncomfortable
