Dysplasia-carcinoma sequence

Question 1

What are some histological features typically seen in dysplastic/malignant cells

Answer 1

• Pleomorphic size
• Atypical nuclei such as mitotic bodies, condensed chromatin and prominent nucleoli
• Dis-organised cell layering
• Features of cell of origin such as keratin pearls, intracellular bridges and glandular structures
• Invading tissues
• Desmoplasia
• Low cytoplasmic to nuclei ration

Question 2

What are pre-malignant cells

Answer 2

They are cells that are disorganised, with one or two features that indicate they are cancerous, however they have not invaded surrounding tissues. Are typically known as carcinomas in situ (CIS)

Question 3

Some examples of metaplasia

Answer 3

Barrett’s Oesophagus in reflux, intestinal metaplasia due to gastritis and squamous metaplasia in smokers or HPV infections

Question 4

Describe the metaplasia observed in HPV infected cervical cells

Answer 4

At time of puberty, the endocervix will be pushed out into the vagina more, causing a physiological metaplasia, however this allows access for HPV to invade. They contain protein virulence factors such as E6 and E7 that degrade the expression of p53 and pRb and hence can promote accumulation of genetic mutations and promotes the development of cancer, Strains 6,11, 16 and 18

Question 5

Describe Barrett’s Oesophagus

Answer 5

Reflux causes stratified sqamous epithelium to undergo changes and metaplasia into columnar epithelium with goblet cells (similar to intestinal). This can promote dysplastic growth and the development of adenocarcinomas