11. What Is Neoplasia

Question 1

What is the definition of a neoplasm?

Answer 1

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

Question 2

What is the definition of 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

Any clinically detectable lump or swelling. A neoplasm is just one type of tumour.

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 non-contiguous site. The original location is the primary site, and the place it has spread to is the secondary site.

Question 6

What is dysplasia? Why is it not neoplastic?

Answer 6

A pre-neoplastic alteration in which cells show disordered tissue recognition due to altered differentiation.
Not neoplastic as the change is reversible.

Question 7

What is the difference in behaviour between a benign neoplasm and a malignant neoplasm?

Answer 7

Benign - remains confined to site of origin and does not produce metastases.
Malignant - have potential to metastasise.

Question 8

What can been seen to the naked eye with benign neoplasms and malignant neoplasms?

Answer 8

Benign - pushing outer margin.

Malignant - irregular outer margin and sharp. May show areas of necrosis and ulceration (if on epithelium).

Question 9

What are anaplastic cells?

Answer 9

Cells with no resemblance to any tissue.

Question 10

What is the difference between the cells seen under a microscope in benign neoplasia and malignant neoplasia?

Answer 10

Benign - cells closely resemble parent tissue, well differentiated.
Malignant - range from well to poorly differentiated.

Question 11

What is seen in an individual cell with worsening differentiation?

Answer 11

Increasing nuclear size.
Increasing nuclear to cytoplasmic ratio.
Increased nuclear staining.
More mitotic figures.
Increasing variation in size and shape of cells and nuclei.

Question 12

What term is used by clinicians to indicate differentiation?

Answer 12

Grade. Higher the grade the more poorly differentiated. Tends to correlate with more aggressive tumours.

Question 13

What do initiators do?

Answer 13

Causes a mutation.

Question 14

What do promotors do?

Answer 14

Cause cell proliferation

Question 15

What do initiators and promotors result in in combination?

Answer 15

An expanded monoclonal (all originating from the same cell) population of mutant cells.

Question 16

What is progression?

Answer 16

The process through which a neoplasm emerges from a monoclonal population, by the accumulation of yet more mutations.

Question 17

In what combination do initiators and promotors need to be given to cause a neoplasia?

Answer 17

An initiator to cause the mutation, and then a promotor for a prolonged period of time to cause cell proliferation and increase the number of cells with the mutation.

Question 18

What are the 3 main initiators? What is one other way that the mutations can come from?

Answer 18

Chemicals, infections, radiation (some also act as promotors). Inherited.

Question 19

What is a neoplasm ending in -oma?

Answer 19

Benign

Question 20

What is a neoplasm ending in -carcinoma?

Answer 20

Epithelial malignant neoplasm (90% of malignant tumours)

Question 21

What is a neoplasm ending in -sarcoma?

Answer 21

Stromal malignant neoplasm

Question 22

What is an in-situ carcinoma?

Answer 22

No invasion through epithelial basement membrane.

Question 23

What is an invasive carcinoma?

Answer 23

Has penetrated through basement membrane.

Question 24

What is leukaemia?

Answer 24

Malignant neoplasm of blood-forming cells arising in the bone marrow.

Question 25

What are lymphomas?

Answer 25

Malignant neoplasms of lymphocytes mainly affecting lymph nodes.

Question 26

What is a myeloma?

Answer 26

Malignant neoplasm of plasma cells.

Question 27

What do germ cell neoplasms arise from, and where?

Answer 27

Arise from pluripotent cells, mainly in the testis or ovary.

Question 28

Where do neuroendocrine tumours arise from?

Answer 28

Cells distributed throughout the body.

Question 29

What are neoplasms ending in -blastoma?

Answer 29

Occur mainly in children, are formed from immature precursor cells eg nephroblastoma.