Oral epithelial dysplasia Flashcards
What is the normal histology of the oral epithelium?
- Replicating basal cells (keratocyte) sit on a basement membrane
- Cells at the bottom are more rectangular/ columnar and nucleus is visibile
- as cells replicate they are pushed towards the surface → cells get flatter (nucleus is not visible)
What are the normal features of a basal cell (keratocyte)
- Nucleus exhibits polarisation (usually at the base)
How is the ratio of nucleus: cytoplasm relevant of a basal cell
- Cells with more abnormalities have a BIGGER nucleus
-Cells replicating a lot have a BIGGER nucleus
What dictates the colour and texture of the epithelium
thickness of epithelial cell layer
What does a red lesion indicate about the thickness of the epithelial cell layer
thin epithelium
What does a white lesion indicate about the thickness of the epithelial cell layer
Thick epithelium
What are the features of dysplasia at a cellular level
- Larger nucleus
-Increased nucleus: cytplasmic ratio - Lose polarity
-More mitotic figures
What is the purpose of a biopsy and how is it conducted for testing?
Fine needle aspiration: take cells out the tissues
Purpose: assess cells and see their arrangement
What features on a biopsy indicate dysplasia
- Disordered maturation (loss of polarity, basaloid appearance throughout whole epithelium)
- Abnormal cell size/ shape (polymorphism, reduced cell cohesion)
- Abnormal replication (nuclear hyperchromatism, increased nuclear size, mitotic figures)
- Abnormal function: abnormal keratinisation (appear white)
What is meant by low grade dysplasia
Normal cells at the top, abnormal cells at the bottom
What is meant by high grade dysplasia
Abnormal cells through full thickness of epithelium
What is rete ridges and their function?
Indentations of basal layer in basement membrane at the interface between epithelial and sub epithelial tissues
function: structural strength to epithelium
True or false: dysplasia can improve & regress spontaneously
TRUE:
- Dysplasia can
- Cancer DOESN’T get better
What dysplastic changes occur to rete ridges
Drop shaped rete ridges: teardrops where rete ridges are pushed down in subepithelial tissues
What is the difference between invasive carcinoma and carcinoma in-situ
Invasive carcinoma: You have cancer, breach in basement membrane: abnormal cells invading through basement membrane
Carcinoma in-situ:
- very abnormal tissues,basement membrane is not breached (not cancer)
