Neoplasia summary

Question 1

Cancer

Answer 1

uncontrolled cell proliferation and growth that can invade other tissues

Question 2

Tumour

Answer 2

swelling can be benign or malignant

Question 3

Neoplasia

Answer 3

new growth which is not in response to a stimulus
- Can be benign, premalignant or malignant
- Can occur in any cell in any organ

Question 4

Malignancy in epithelium

Answer 4

goes beyond the basement membrane- invasion
Access to blood vessels, lymph nodes

Question 5

Dysplasia

Answer 5

abnormal cells growing without a stimulus
-no invasion
-often graded- higher grades have a higher risk of developing malignancy

Question 6

Carcinoma in-situ

Answer 6

dysplasia affecting whole of epithelium
last stage before becoming malignant

Question 7

Metaplasia

Answer 7

reversible change from one mature cell type to another mature cell type

Question 8

Metaplasia cause

Answer 8

due to change in the demand placed on tissue
- due to noxious stimulus

Question 9

Metaplasia in epithelium

Answer 9

1. Squamous epithelium covers skin and is very resistant to a range of noxious stimuli - metaplasia often encountered in response to injury
2. Thermal/chemical injury (e.g. smoking) to bronchial epithelium in the lung → squamous epithelium
3. Catheter creates inflammation in the bladder → transitional epithelium changes to squamous

Question 10

Double hit hypothesis

Answer 10

• One working gene is enough
• One faulty gene puts person at increased risk
• Two faulty mutated genes will result in a functional problem

Question 11

Chemical carcinogens- Initiators

Answer 11

long lasting genetic damage, not sufficient to cause cancer – must be followed by a promoter

Question 12

Promoters

Answer 12

require initiators to have caused damage, time period can vary after initiation

Question 13

Smoking

Answer 13

> 40 carcinogens, e.g. polycyclic aromatic hydrocarbons