OC 11 - pathogenesis of HNC 3

Question 1

What is dysplasia?

Answer 1

a pre-malignant process

can be identified in many tissues

Question 2

In tumour growth, what is the “initial event”?

Answer 2

initial event is where DNA damage occurs

Question 3

In tumour growth, what is “mild dysplasia”?

Answer 3

damage has led to atypical proliferation of cells, but this is contained within the epithelium

Question 4

In tumour growth, what is “severe dysplasia”?

Answer 4

full thickness of epithelium becomes involved - not invasive malignancy yet though because the tumour cells are still in the surface epithelium and havent breached the basement membrane

Question 5

In tumour growth, what is “invasive malignancy”?

Answer 5

tumour cells have breached the basement membrane and are invading surrounding tissue

Question 6

What is epithelial dysplasia?

Answer 6

a premalignant process - indicates a risk of developing carcinoma

Question 7

In epithelial dysplasia, where are atypical epithelial alterations limited to?

Answer 7

limited to the surface squamous epithelium

Question 8

What are architectural changes?

Answer 8

maturation and differentiation

Question 9

What are cytological changes?

Answer 9

changes in cells

Question 10

What is the key point to remember about epithelial dysplasia!

Answer 10

cells show abnormal features that are also seen in cancer cells but they do not yet possess the ability to invade adjacent normal tissues

Question 11

What are the histological features of epithelial dysplasia?

Answer 11

1. nuclear and cellular pleomorphism
2. alteration in nuclear/cytoplasmic ratio (invariably an increase)
3. nuclear hyperchromatism
4. prominent nucleoli
5. increased and abnormal mitoses
6. loss of polarity of basal cells
7. basal cell hyperplasia
8. drop-shaped rete pegs
9. irregular epithelial stratification or disturbed maturation
10. abnormal keratinisation (dyskeratosis)
11. loss/reduction of intercellular adhesion

Question 12

What is nuclear and cellular pleomorphism?

Answer 12

variation in the size and shape of the nuclei and the cells themselves

Question 13

What are ‘drop-shaped’ rete pegs?

Answer 13

wider at their deepest part

Question 14

What is dyskeratosis?

Answer 14

cells start to keratinise before the surface is reached

Question 15

What makes oral epithelial dysplasia different to oral SCC?

Answer 15

in dysplasia the atypical cells are confined to the surface, in SCC the atypical cells invade into the underlying connective tissue

Question 16

What are the 3 categories in the WHO 2017 grading of epithelial dysplasia?

Answer 16

mild
moderate
severe (= carcinoma in situ)

Question 17

What are the WHO 2017 gradings of epithelia dysplasia based on?

Answer 17

based on 1/3 of epithelium

Question 18

What are the characteristics of mild dysplasia?

Answer 18

disorganisation, increased proliferation and atypia of basal cells

basal 1/3 of epithelium

Question 19

What are the characteristics of moderate dysplasia?

Answer 19

more layers of disorganised basaloid cells, atypia, suprabasal mitoses

extending to 2/3rds of the epithelium (basal and middle third)

Question 20

What are the characteristics of severe dysplasia?

Answer 20

very abnormal, affects full thickness of epithelium (all 3rds)

Question 21

What are oral potentially malignant disorders?

Answer 21

oral mucosal lesions that have a potential risk of developing into oral SCC

Question 22

What are some oral potentially malignant disorders?

Answer 22

• Leukoplakia
• Erythroplakia
• Erythroleukoplakia
• Oral submucous fibrosis
• Syphilitic glossitis
• Dyskeratosis congenita
• Chronic candidiasis
• Lichen planus
• Discoid lupus erythematosus
• Smokeless tobacco keratosis
• Palatal lesions associated with reverse smoking
• Actinic keratosis (lip only)

Question 23

What is oral submucous fibrosis?

Answer 23

pale fibrous bands
- progressive deposition of collagen in the submucosal tissue, also associated with atrophy of the surface epithelium