Growth, Cell death & Neoplasia

Question 1

Define multiplicative growth

Answer 1

Increase in number of cells by mitotic cell divisions

Question 2

Define auxetic growth

Answer 2

Increase in size of individual cells eg. Skeletal muscle

Question 3

Define accretionary growth

Answer 3

Increase in intercellular tissue components

Question 4

Define atrophy

Answer 4

Decrease in size of an organ or cell either physiological or pathological

Question 5

Define hyperplasia

Answer 5

Increase in cell number by mitosis, may be due to decreased apoptosis

Question 6

Define hypertrophy

Answer 6

Increase in cell size without cell division, in permanent cells it is the only option for growth

Question 7

Define metaplasia

Answer 7

Reversible transformation of one fully differentiated cell type into another. It is an adaptive response to environmental stress. eg squamous epithelium –> columnar epithelium in Barrett’s oesophagus

Question 8

3 characteristics of dysplasia

Answer 8

Increased cell growth, presence of atypical morphology, decreased differentiation, often pre-neoplastic, may be reversible in early stage

Question 9

3 differences between apoptosis and necrosis

Answer 9

Apoptosis natural, necrosis caused by external factors. Apoptosis usually beneficial, necrosis always detrimental.
Apoptosis no symptoms, necrosis evokes an inflammatory response.

Question 10

5 types of necrosis

Answer 10

Gangrenous, coagulative, colliquative, caseous, fat necrosis

Question 11

Define neoplasia

Answer 11

Abnormal, uncoordinated and excessive cell growth which persists when the stimulus is removed

Question 12

Define a tumour

Answer 12

A lesion resulting from the autonomous and abnormal growth of cells which persists after the initial stimulus has been removed

Question 13

Name 6 different shapes of tumours

Answer 13

Sessile, pedunculated, fungating, papillary, ulcerated, annular

Question 14

4 histological differences of neoplasms to normal tissue

Answer 14

Increased mitotic activity, loss of cellular cohesion, loss of differentiation, nuclear enlargement

Question 15

8 inducers of apotosis

Answer 15

Growth factor withdrawal, loss of matrix attachment, glucocorticoids, viruses, free radicals, ionising radiation, DNA damage, FAS ligand

Question 16

4 inhibitors of apoptosis

Answer 16

Growth factors, cell matrix, sex steroids, some proteins

Question 17

Describe the process of apoptosis

Answer 17

Degradation of cytoskeletal framework, DNA fragments, loss of mitochondrial function, nucleus shrinks (pyknosis) and fragments (karyorrhexis), cell shrinks but retains intact plasma membrane. Dead cells not phagocytosed break into apototic bodies - no inflammatory response.

Question 18

What two factors are tumours classified according to?

Answer 18

Behaviour (benign or malignant) and histogenesis (cell of origin)

Question 19

5 features of benign tumours

Answer 19

Close histological resemblance to parent tissue, non invasive, remain localised, slow growth, exophytic growth

Question 20

5 features of malignant tumours

Answer 20

Variable resemblance to parent tissue, ability to invade and therefore metastasise, rapid growing, endophytic growth

Question 21

5 clinical problems benign tumours can cause

Answer 21

Anxiety, pressure on surrounding structures, production of hormones, transformation into a malignant neoplasm, obstruction of the flow of fluid

Question 22

7 clinical problems malignant tumours cause

Answer 22

Pressure on/destruction of adjacent tissue, secondary tumours, anxiety, pain, paraneoplastic effects, blood loss, obstruction of flow, production of a hormone

Question 23

3 major histogenetic classifications

Answer 23

Epithelial, connective tissue, lymphoid/haemopoeitic organs

Question 24

Define differentiation

Answer 24

The degree to which the tumour resembles histologically its cell of origin, it determines the tumour grade

Question 25

What is a papilloma?

Answer 25

Benign tumour of non glandular/non secretory epithelium

Question 26

What is an adenoma?

Answer 26

Benign tumour of secretory/glandular epithelium

Question 27

What is a carcinoma?

Answer 27

Malignant tumour of non glandular epithelium

Question 28

What is an adenocarcinoma?

Answer 28

Malignant tumour of glandular epithelium

Question 29

What is a carcinoma in situ?

Answer 29

Epithelial neoplasm that has not yet invaded through the basement membrane. Only at this stage will excision guarantee a cure.

Question 30

How are benign mesenchymal tumour named?

Answer 30

After the cell/tissue of origin suffixed by ‘oma’ eg Lipoma - benign tumour of lipocytes

Question 31

What is a sarcoma?

Answer 31

Malignant tumour of mesenchyme/connective tissue. (prefixed by the cell/tissue of origin, eg. Osteosarcoma)

Question 32

What is a teratoma?

Answer 32

A neoplasm formed of cells representing all 3 germ layers - ectoderm, mesoderm and endoderm

Question 33

What are the two categories of tumour suppressor genes?

Answer 33

Caretaker genes (BRCA)- maintain integrity by repairing damaged DNA. Gatekeeper (p53) genes inhibit proliferation or promote death of cells with damaged DNA

Question 34

2 normal functions of p53

Answer 34

Repair of DNA by arresting the cell cycle in G1 until damage is repaired. Apoptotic cell death if damage is extensive

Question 35

Where is p53 situated?

Answer 35

Short arm of chromosome 17. (most frequently mutated)

Question 36

3 ways p53 can lose its normal function

Answer 36

Mutations (non sense or mis sense). Complexes of mutant and normal p53 inactivating the function of the normal allele. Binding of normal p53 protein to oncogenic DNA viruses.