Potentially Malignant Disorders And Oral Cancer Flashcards
Define potentially malignant lesion
Altered tissue in which cancer is more likely to form
Define potentially malignant CONDITION
Generalised state with increased cancer risk
Give some potentially malignant conditions
Lichen planus
Iron deficiency - reduced barrier to carcinogen so more oxidative stress and free radical production
Tertiary syphillis
Give some potentially malignant LESIONS
Erythroplakia
Leukoplakia
- CHC
- proliferaitve verrucous leukoplakia
What is CHC?
Variant of oral candidiasis
- often occurs at commissures of mouth
- often found in smokers
- dysplasia may be present
How can CHC be shown histopathologically?
PAS (periodic Schiff stain)
- highlights candidal hyphae on staining
- shows prescence of C.albicans
Tx of CHC?
Systemic antifungal
- fluconazole, 14 days
Biopsy
stop smoking
What clinical predictors may indicate malignancy in leukoplakia?
Age and gender of pt
Idiopathic cause
High risk site
- FOM and tongue
Clinical appearance
- non homogenous, verrucous, ulcerated or Leuko-erythroplakia
Biggest predictors for malignant change histopathologically?
Dysplasia
Atrophy
Candida infection
What is dysplasia?
Disordered maturation (growth) in a tissue
What is cellular atypica?
Changes in cells
How does one go about diagnosing potentially malignant lesion histopathologically?
Fist look at architectural changes
Then assess cytology of the tissue
How can one GRADE epithelial dysplasia
HYPERPLASIA
MILD
MODERATE
SEVERE
CARCINOMA IN SITU
What is basal hyperplasia?
Increased number of basal cells
Architecture
- regular stratification of layers
- basal cell layer enlarged
Cytology
- no cellular atypia
How would the grade: mild dysplasia appear histopathologically?
Architecture
- changes in lower third
Cytology - mild atypia
- pleomorphism of cells
- hyperchromatism of cells
- basal cell hyperplasia
How would the grade: moderate dysplasia present histopathologically?
Architecture
- middle third extension of changes
Cytology
- moderate cellular atypia
How would the grade: severe dysplasia present histopathologically?
Architecture - changes extending into upper third
Cytology
- severe atypia
- numerous mitoses
How might carcinoma in situ present histopathologically?
Architecture
- abnormal
- full thickness changes
Cytology
- pronounced atypia
- frequent mitosis abnormalities
What genes are involved in oral cancer progression?
Oncogenes and TSG
TP53 TSG
Genes that regulate apoptosis
Genes involved in DNA repair
Viral genes??
how can gene expression be altered?
TSG and oncogenes
DNA methylation
Histone modification
Gene mutation
What are the 6 hallmarks of cancer
Self sufficient growth signals
Insensitivity to growth inhibition signals
Tissue invasion and metastases
Limitless replicative potential
Self sustained angiogenesis
Evading apoptosis
How is the pattern of invasive front related to nodal spread?
Non-cohesive front of invasion is more linked to nodal spread
How does oral cancer spread through the tissues?
- Local invasion of disease to adjacent tissues
- Lymphatic spread
- Haematogenous spread
How can oral cancer spread to bone?
Through gaps in the cortex of the bone in edentulous spaces
Through a dentate individual via the PDL
