tumour biology

Question 1

differentiation invloves…

Answer 1

• the inactivation of proliferation genes

- the activation of specific function genes

Question 2

de-differentiation involves…

Answer 2

reversion to primitive, embryonic and proliferative phenotypes as occurs in neoplasia
(involved in cancer)

Question 3

disorders of growth refers to…

Answer 3

the regulation of proliferation or differentiation

Question 4

agenesis

Answer 4

the total absence of structure or organ

Question 5

hypoplasia

Answer 5

congenital reduction in size

Question 6

atrophy

Answer 6

acquired reduction in size

Question 7

hyperplasia

Answer 7

increased number of cells

Question 8

hypertrophy

Answer 8

• can refer to both cells or whole organs

- is an increase in size

Question 9

premalignant

Answer 9

a statistical concept relating to an increased probability of developing into cancer

Question 10

causes of hyperplasia

Answer 10

• chronic irritant e.g. ulcer
• endocrine stimulation
• “functional” physiological

Question 11

effects of hyperplasia

Answer 11

increased function

risk of malignancy (for some types)

Question 12

metaplasia

Answer 12

change from one mature tissue type to another

• some are premalignant
• caused by change in environment or irritation

Question 13

dysplasia

Answer 13

• only seen under the microscope (histological abnormality)
• all are premalignant
• is the partial malignant transformation
• various grades
• cells are clonal
  opportunity to remove tissues, prevent invasive cancer

Question 14

neoplasia

Answer 14

new growth

Question 15

another name for dysplasia

Answer 15

intraepithelial neoplasia

Question 16

reactive atypia

Answer 16

after injury cells carry out regeneration and proliferate. As a result of increased rates of turnover, cells are at risk of genetic abnormalities and cells can look like dysplasia

Question 17

the difference between benign and malignant neoplasms

Answer 17

benign:

• do not metastasize
• cells are differentiated
• expansile growth
• rarely fatal

malignant

• most types metastasize
• cells less differentiated
• infiltrative growth, rapid
• fatal if untreated

Question 18

components of solid tumours seen under microscope

Answer 18

• new blood vessels forming
• immune response
• production of fibrosis tissue

Question 19

tumour stroma

Answer 19

everyting in the tumour apart from the cells

• fibroblast, collagen, matrix
• new blood vessels
• inflammatory cells

Question 20

tumour cell hypoxia

Answer 20

uncoordinated growth of cells causes new vessels to form uncontrollably. As a result not all cells are insufficiently supplied with oxygen causing necrotic tissue to occur

• illustrated high grade tumour if large number of necrotic tissue
• hypoxic cells are resistant to radiation

Question 21

what is the pathological diagnosis when you know a cell is malignanat

Answer 21

• stage
• grade
• type

Question 22

microscopic diagnosis of malignancy

Answer 22

• architecture
  e. g. disorganised, invasion of normal tissue
• cell features
  e. g. increased nuclear size, variation in shape, mitoses, decreased cell cohesion

Question 23

how does stroma cells prevent growth of tumours

Answer 23

• apoptosis
• DNA repair damage
• immunosurveillance

Question 24

anaplasia

Answer 24

lack of differentiation

Question 25

define heterogeneity

Answer 25

the difference in cell genes | - consequently means resistance can occur

Question 26

how could mutations in DNA mismatch repair genes promote the formation of tumours

Answer 26

as DNA is being replicated DNA repair genes are being cycled to detect any errors intoduced. However a mutation in DNA mismatch repair genes means there is greater risk for cells to acquire mutations causing cancer

Question 27

how do cancer cells avoid immune effectors

Answer 27

- decrease in HLA class 1 expression - resistance to immune attack - release immune inhibitors - amino acid depletion (deplete environment) - activate inhibitory T cells - poor immunogenicity