Pathology 2 - Potentially malignant lesions Flashcards
Define a potentially malignant lesion.
Altered tissue in which cancer is more likely to form
Define a potentially malignant condition.
Generalised state with increased cancer risk
Give examples of potentially malignant conditions.
- lichen planus
- oral submucous fibrosis
- iron deficiency
- tertiary syphilis
Why is an iron deficiency a potentially malignant condition?
Iron deficiency thins the mucosa which makes it easier to carcinogens to penetrate
Which lesions have a higher transformation rate?
- leukoplakia
- chronic hyperplastic candidiasis
- proliferative verrucous leukoplakia
- erythroplakia
What is chronic hyperplastic candidiasis also known as?
Candidal leukoplakia
Where is chronic hyperplastic candidiasis typically found?
Commissures of smokers
How is chronic hyperplastic candidiasis managed?
- systemic antifungal (fluconazole)
- biopsy
- smoking cessation
- observation
From where do most oral carcinomas arise in the UK?
Clinically normal mucosa
What is the transformation risk of leukoplakia?
50-100x risk than clinically normal mucosa
What factors increase the risk of transformation of leukoplakia?
- age
- female
- FOM or tongue are high risk sites
- non-homogeneous appearance
What does altered or missing p53 indicate as a molecular marker?
- p53 is a tumour suppressor gene
- changes indicate progression of a lesion
What impact does a positive result for HPV in a tumour have?
Tumours that are positive for HPV have a better prognosis than those that are negative
Define dysplasia.
Disordered maturation in a tissue
Define atypia.
Changes within cells
What can be observed in histopathology slides to aid diagnosis?
- architectural changes
- cytological abnormalities
What are the grading of epithelial dysplasia?
- hyperplasia
- mild
- moderate
- severe
- carcinoma-in-situ
Can you grade epithelial dysplasia clinically?
No - a microscopic diagnosis
Describe basal hyperplasia.
- increased basal cell numbers
- regular stratification but basal compartment is larger
- no cellular atypia (!)
Describe mild dysplasia.
- changes to architecture in lower third
- mild cellular atypia (not all cells show changes)
Define pleomorphism.
Variety of shapes and sizes of cells or cellular components
Define hyperchromatism.
Cells stain darker due to increase in DNA
Describe moderate dysplasia.
- changes to architecture extending into middle third
- moderate atypia
Describe severe dysplasia.
- architectural changes extend into more than 2/3 of epithelium
- most cells are affected by atypia
- numerous mitoses, loss of polarity and mitotic figures
Describe carcinoma-in-situ.
- theoretic concept
- malignant but not invasive (ie confined within epithelium)
- full thickness changes to architecture
- pronounced cellular atypical with frequent mitotic abnormalities
- degree of inflammation
What is the gold standard for detection and diagnosis of oral cancer?
- visual detection
- histopathology for diagnosis
What are screening tools that may be used in the future?
- salivary biomarkers
- NGS
- AI
What are the two main factors in carcinogenesis?
- genetics
- environmental (carcinogens)
What is the molecular basis of cancer?
- damage
- altered gene expression
- altered cell function
What genes are involved in the progression of cancers?
- oncogenes
- tumour suppressor genes (eg p53)
- genes that regulate apoptosis
- genes involved in DNA repair
- miRNA
Define aneuploidy.
Changes in number of chromosomes
Define translocation.
DNA strands break and reattach in different location
Define amplification.
Extra copies of genes or chromosomes
What are epigenetic changes?
- chemical changes in DNA
- modification of histones
What are the six hallmarks of cancer?
- evading apoptosis
- self-sufficiency in growth signals
- insensitivity to anti-growth signals
- tissue invasion and metastasis
- limitless replicative potential
- sustained angiogenesis
What is the difference between a cohesive front and a non-cohesive front?
- cohesive front, all cells advance at the same rate
- non-cohesive front see cells advancing at different rates and is more likely to involve nodes
How can oral cancer spread?
- local extension
- lymphatic spread
- haematogenous spread
Describe local extension of oral cancer.
- depends on site
- can extend further into mucosa
- can spread to muscle, bone or nerves
How does oral cancer spread into bone?
- in edentulous patients can spread via gaps in cortex
- in dentate patients can spread via PDL
What prognosis does perineural spread have?
- spread at small nerves it predictive of nodal spread
- extensive spread via IAN can predict recurrence
What are the different types of lymphatic spread of oral cancer?
- embolism
- extracapsular spread
- permeation (growth within nodes)
What is a sentinal node biopsy?
Principle draining lymph node is biopsied
What are the OSCC subtypes?
- verdurous carcinoma
- basaloid squamous (HPV)
- spindle cell (aggressive)
What is the haematogenous spread of oral cancer?
- spread via blood vessels
- late stage feature
- can spread to lungs, spine etc
