Pathogenesis of Head and Neck cancer 3 Flashcards
What are the stages of tumour growth?
- Normal
- Initial event
- Mild Dysplasia
- Severe Dysplasia
- Invasive Malignancy
(black line demonstrateds basement membrane)
What is Dysplasia?
A pre-malignant process
Can be identified in many tissues
Epithelia are a good example
→Squamous
→Glandular
What is Epithelial Dysplasia?
A premalignant process- indicates a risk of developing carcinoma
Atypical epithelial alterations limited to the surface squamous epithelium-
Architectural changes- maturation and differentiation
Cytological changes- changes in cells
Cells show abnormal features that are also seen in cancer cells but they do not yet possess the ability to invade adjacent normal tissues
What are Histological features of epithelial dysplasia?
- Nuclear and cellular pleomorphism
- Alteration in nuclear/cytoplasmic ratio (invariably an increase)
- Nuclear hyperchromatism
- Prominent nucleoli
- Increased and abnormal mitoses
- Loss of polarity of basal cells
- Basal cell hyperplasia
- Drop-shaped rete pegs ie wider at their deepest part
- Irregular epithelial stratification or disturbed maturation
- Abnormal keratinization (Dyskeratosis- cell starts to keratinize before the surface is reached)
- Loss/ reduction of intercellular adhesion
What is the difference between dysplasia and SCC with regards to atypical cells?
In dysplasia the atypical cells are confined to the surface.
In SCC, the atypical cells invade into the underlying connective tissue.
What is the Epithelial Dysplasia “WHO 2017 Grading- based on 1/3 of epithelium”?
Mild- disorganisation, increased proliferation and atypia of basal cells
Moderate- more layers of disorganised basaloid cells, atypia, suprabasal mitoses
Severe- very abnormal, affects full thickness of epithelium
In this diagram of severe dysplasia where is the Atypical mitosis and Dyskeratotic cell?
