Oral Surgery & Histopathology Flashcards
SCR
What are the red flag signs of oral squamous cell carcinomas??
- Non-healing ulcers
- Non-homogenous leukoplakia
- Erythroplakia
- Induration
- Tooth mobility [unexplained]
- Pathological fracture [unexplained]
- Cervical lymphadenopathy
What are the red flag symptoms of oral squamous cell carcinomas??
- Discomfort and pain
- Loss of sensation over the distribution of CNV
- Difficulty eating, swallowing & speaking
- Loss of apetite, weight loss & fatigue
What do odontogenic cysts and tumours arise from?
Inclusion of tooth-forming epithelium and mesenchyme in the jaw bones during development
What is the most common odontogenic tumour?
Ameloblastoma
What are some epithelial-lined odontogenic cysts?
- radicular cyst
- residual cyst
- dentigerous cyst
- eruption cyst
- odontogenic keratocyst
- lateral periodontal cyst
- gingival cyst
What are some epithelial-lined non-odontogenic cysts?
- nasopalatine duct cyst
- nasolabial cyst
What are some non- epithelial-lined jaw cysts?
- solitary bone cyst
- aneurysmal bone cyst
What is the definition of a cyst?
a pathological cavity having fluid or semi-fluid contents that has not been created by the accumulation of pus
Discuss the location of a radicular cyst:
- always associated with a non-vital tooth
- periapical region
Discuss the clinical features of a radicular cyst:
- most common jaw cyst
- often symptomless
- incidental finding
- slowly expanding
Discuss the histopathology of a radicular cyst:
- thick, inflamed fibrous capsule
- non-keratinising squamous epithelial lining
- cholesterol nodules
- Rushton’s bodies
Discuss the location of a residual cyst:
- site of a previously extracted non vital tooth
- most common in mandibular premolar area
Discuss the clinical features of a residual cyst:
- slowly enlarging swelling
- symptomless
Discuss the histopathology of a residual cyst:
- thick fibrous capsule
- non-keratinising squamous epithelial lining
- chloesterol nodules
Discuss the location of a dentigerous cyst:
- associated with an unerupted tooth
Discuss the clinical features of a dentigerous cyst:
- develop around crowns of unerupted teeth
- may displace tooth
Discuss the histopathology of a dentigerous cyst:
- capsule resembles dental follicle
- myxoid areas and odontogenic rests
- lined by reduced enamel epithlium
Discuss the location of a odontogenic keratocyst:
Majority:
- angle of mandible
- posterior maxilla
Discuss the clinical features of a odontogenic keratocyst:
- multilocular radiolucency
- expands through medullary bone
- minimal cortical expansion
- RECURRANCE
Discuss the histopathology of a odontogenic keratocyst:
- thin, fibrous capsule
- lined by parakeratotic squamous epithelium
- basal cell palisade
- satellite cysts
- occurs commonly in basal cell nevus syndrome
What syndrome are multiple odontogenic keratocysts associated with ?
basal cell nevus syndrome (Gorlin-Goltz syndrome)
Discuss the location of a nasopalatine duct cyst:
floor of nose to incisive papilla
Discuss the clinical features of a nasopalatine duct cyst:
- swelling
- displacement of central incisors
- salty taste
- radiolucency >6mm
- vital adjacent teeth
Discuss the histopathology of a nasopalatine duct cyst:
- fibrous capsule
- lined by respiratory or simple squamous epithelium or both
Where does the epithelial lining of odontogenic cysts originate from?
- Epithelial Rests of Serres
- Reduced Enamel Epithelium
- Epithelial rests of Malassez
What are Epithelial rests of Serres & what cysts do they give rise to?
- remnants of dental lamina
- odontogenic keratocyst
- lateral periodontal
- gingival cyst
What is Reduced enamel epithelium & what cysts does it give rise to?
- Derived from enamel organ & covers the fully formed crown of unerupted tooth
- Dentigerous cysts
- Paradental cysts
What are Epithelial rests of Malassez & what cysts do they give rise to?
- Form by fragmentation of Hertwig’s epithelial root sheath
- Radicular cysts
What are the most common type of jaw cyst?
Radicular
How does the expansion of a cyst present clinically?
Egg shell crackling on palpation due to thinning of bone cortex
How does a radicular cyst present radiographically?
Round or ovoid radiolucency at the root apex
- corticated margins continuous with lamina dura of tooth
What is the pathogenesis of radicular cysts?
Proliferation of the epithelial rests of Malassez within chronic periapical granulomas due to:
- necrotic pulp
Discuss the contents of a radicular cyst if it were to be aspirated:
Watery, straw coloured fluid
OR
Semi-solid brownish material
- breakdown products of degenerating epithelial & inflammatory cells & connective tissue components
- serum proteins
- water & electrolytes
- cholesterol crystals
Discuss the radiographic findings of a dentigerous cyst:
Well-defined, unilocular radiolucency associated with the crown of an unerupted tooth
- the tooth may be displaced for a considerable distance
Describe the histopathological findings of a dentigerous cyst:
- lined by non-keratinised stratified squamous or flattened cuboidal epithelium
- resembles reduced enamel epithelium
- fibrous capsule containing loose myxoid areas resembling dental follicle
Discuss the findings if you were to aspirate a dentigerous cyst:
- proteinaceous, yellow fluid
- cholesterol crystals common
How common are odontogenic keratocysts?
5-10% of jaw cysts
When is the peak age/incidence of development of an odontogenic keratocyst?
2nd/3rd decade
Where is the most common site for development of an odontogenic keratocyst?
Mandible (third molar region most common)
Why do patients with odontogenic keratocysts tend to present so late?
These cysts give rise to very few symptoms
How do odontogenic keratocysts appear radiographically?
Commonly multilocular
What syndrome is associated with multiple odontogenic keratocysts? How is this inherited?
Basal cell nevus syndrome (Gorlin-Goltz syndrome)
- autosomal dominant trait
What is an important clinical feature of odontogenic keratocysts?
High recurrence rate
Discuss the growth pattern of the odontogenic keratocyst:
Destructive pattern of growth
- burrows through cancellous bone in an AP direction
What is the aetiology of the nasopalatine duct cyst?
Arises from epithelial remnants of the nasopalatine duct that connects the oral & nasal cavities
What are the clinical features of a nasopalatine duct cyst?
Can present as a slowly enlarging swelling in anterior midline of palate
- discharge may cause salty taste
-
Discuss the radiographic findings of a nasopalatine duct cyst:
Well defined round/ovoid/heart-shaped radiolucencies with corticated margins
Discuss the histopathological findings of a nasopalatine duct cyst:
Combination of:
- stratified squamous
- pseudostratified ciliated columnar
- cuboidal & columnar epithelium
With connective tissue capsule
What provisional diagnoses may you come up with for a nasopalatine duct cyst?
- nasolabial cyst
- median palatal cyst
What type of cyst presents on a radiograph as “scalloping around & between the roots of standing teeth, most frequently in the premolar/molar regions” and it has clear/blood stained fluid on aspiration:
Solitary bone cyst
Do solitary bone cysts have an epithelial lining?
NO [non-odontogenic cyst]
What is a Staphne cavity?
Idiopathic developmental bone cavity located on mandible
- round, well demarcated radiolucency between premolar region & angle of jaw
- usually below IAN canal
What syndrome is associated with multiple odontomes?
Gardner’s syndrome
How does a complex odontome appear histologically?
Mass of disordered (but well formed) enamel, dentine and cementum
What are odontomes?
Hamartomatous developmental lesions that can cause delay in eruption of permanent teeth
What is the most frequent benign odontogenic tumour?
AMELOBLASTOMA
- locally invasive neoplasm
- high recurrence rate
What are the histopathological findings of Follicular Ameloblastomas?
- islands of odontogenic eptihelium within fibrous stroma
- columnar basal cell palisading
- central cells loosely arranged resembling stellate reticulum
- reverse polarity of nuclei
How are ameloblastomas managed?
Excision of area with a margin of uninvolved tissue to reduce chance of recurrence
- long term follow up mandatory
What systems are in place for grading epithelial dysplasia?
WHO system and Binary system (WHO more common for oral pathology)
How can cysts be classified?
Based on WHO 2017 Classification
How does the 2017 WHO classification divide cysts?
- Odontogenic Cysts of Inflammatory Origin
- Odontogenic Cysts of Developmental Origin
- Non-Odontogenic Epithelial Cysts
- Non-epithelial cysts
What cysts come under “Odontogenic Cysts of Inflammatory Origin”?
- Radicular Cysts
- Inflammatory Collateral Cysts [paradental cysts & mandibular buccal bifurcation cyst]
What cysts come under Odontogenic Cysts of Developmental Origin?
- Dentigerous Cyst
- Odontogenic Keratocyst
- Lateral Periodontal Cyst
- Gingival Cysts
- Calcifying Odontogenic Cyst
What cysts fall under “non-odontogenic epithelial cysts”?
- Nasolabial cysts
- Nasopalatine cyst
What cysts fall into the Non-Epithelial Cysts class?
- solitary bone cyst
- aneurysmal bone cyst
- stafne idiopathic bone cavity
What is the most common jaw cyst?
Radicular cyst (60%)
What do radicular cysts originate from?
Inflammation [arising from necrotic pulp] leading to proliferation of epithelial rests of Malassez
- these originate from Hertwig’s root sheath (dental follicle)
How are radicular cysts treated?
Enucleation & removal of associated tooth
What is the incidence of inflammatory collateral cysts?
5% of odontogenic cysts
What are Paradental Cysts?
Cysts associated with a partially erupted tooth (most frequently third molars)
What is the most common developmental odontogenic cyst?
Dentigerous cysts (form 20% of all odontogenic cysts)
What provisional diagnoses may you come up with for a dentigerous cyst?
- dentigerous cyst
- adenomatoid odontogenic tumour
- calcifying epithelial odontogenic tumour
How are dentigerous cysts treated?
Enucleation with associated tooth
(marsupialisation if large)
How do dentigerous cysts present clinically?
- males > females
- 2nd & 3rd decade
- asymptomatic, often incidental finding
- tooth missing from arch
What is the radiographic presentation of a dentigerous cyst?
- round/ovoid
- well-defined unilocular, uniform radiolucency
- attached to CEJ of unerupted tooth
What are the contents of a dentigerous cyst?
- Proteinaceous, yellow fluid
- Cholesterol crystals common
What is basal cell naevus syndrome? How does it occur?
- Autosomal dominant trait
Presentation:
- multiple OKCs
- multiple naevoid BCCs of skin
- skeletal abnormalities
What is cyst enucleation?
Removal of entire cyst lining & contents
- useful for radicular/residual cysts, dentigerous cysts, keratocysts
In what scenario is enucleation unsuitable?
Ameloblastoma
What complications may arise from enucleation of cysts?
- damage to IAN
- communication with sinus (OAC)
- pathological fracture of mandible
- risk of recurrence
