Neoplasm

Question 1

What is a neoplasm?

Answer 1

An abnormal growth of cells that persists after the initial stimulus is removed

Question 2

What is a malignant neoplasm?

Answer 2

An abnormal growth of cells that persists after the initial stimulus is removed and invades surrounding tissue with potential to spread to distant sites

Question 3

What is a tumour?

Answer 3

Clinically detectable lump/swelling

Question 4

What is a cancer?

Answer 4

Any malignant neoplasm

Question 5

What is a metastasis?

Answer 5

A malignant neoplasm that has spread from its original site to a new site

Question 6

What is dysplasia?

Answer 6

Pre-neoplastic alteration in which cells show disordered tissue organisation

Question 7

What are features of benign neoplasms?

Answer 7

Confined to site of origin
Pushing outer margin
Do not metastasise

Question 8

What are features of malignant neoplasms?

Answer 8

Potential to metastasise

Irregular outer margin

Question 9

What are microscopic features of benign neoplasms?

Answer 9

Well differentiated - resemble parent tissue

Question 10

What are microscopic features of malignant neoplasms?

Answer 10

Increased nuclear size
Increased nuclear:cytoplasmic ratio
Hyperchromasia - increased nucleus staining
More mitotic figures
Pleomorphism - increased variation in size and shape

Question 11

What are anaplastic cells?

Answer 11

Cells with no resemblance to any tissue

Question 12

What causes neoplasms?

Answer 12

Accumulated mutations

Mutations caused by

• initiators (mutagenic agents)
• promoters (cause cell proliferation)

Question 13

What can be initiators?

Answer 13

Chemicals
Infection
Radiation

Question 14

What does monoclonal mean?

Answer 14

Originating from a single cell type

Question 15

What is progression?

Answer 15

Neoplasm emerges from a monoclonal population by accumulating multiple mutations

Question 16

What are proto-oncogenes?

Answer 16

A normal gene that when abnormally activated becomes an oncogene - favouring neoplasm formation

Question 17

What is a tumour suppressor gene?

Answer 17

Genes which suppress neoplasm formation

Can become inactivated

Question 18

How does a tumour metastasise?

Answer 18

Grow and invade at primary site
Enter transport system
Lodge at secondary site
Grow at secondary site (colonisation)

Avoid destruction by immune cells

Question 19

What is EMT?

Answer 19

Epithelial-to-mesenchymal transition
- changes that create a carcinoma cell type that looks more like a mesenchymal cell than an epithelial cell

Changes

• adhesion
• proteolysis
• motility

Question 20

What is adhesion?

Answer 20

Reduction in E-cadherin expression

Changes in integrin expression

Question 21

What is proteolysis?

Answer 21

Degradation of basement membrane/stroma

Altered expression of MMPs (protease)

Question 22

What is motility?

Answer 22

Changes in actin cytoskeleton

Question 23

How can malignant cells travel to distant sites?

Answer 23

Blood vessels
Lymphatics
Transcoelomic spread

Question 24

What is colonisation?

Answer 24

Malignant cells grow at a distant site to origin

Question 25

What is tumour dormancy?

Answer 25

A disease free person can harbour many micrometastases

Question 26

What are local effects of neoplasms?

Answer 26

Direct invasion
Ulceration
Compression of structures
Blockage of tubes

Question 27

What are systemic effects of neoplasms?

Answer 27

Immunosupression 
Weight loss (cachexia)
Thrombosis
Inappropriate hormone production
Neuropathies