The behaviour of tumour

Question 1

What are the 3 ways tumours are classified by?

Answer 1

1. differentiation state
2. Embryonic origin
3. Biological behaviour (malignant/benign)

Question 2

How can tumour embryonic origins be subclassified by?

Answer 2

1. epithelial
2. non-epithelial
3. Mixed (eg. carcinosarcoma)

Question 3

What are the different embryonic origin of tumours?

Answer 3

1. Ectoderm (epithelia/nervous)
2. Mesoderm (epithelia/Bone/soft tissue)
3. Endoderm (epithelia)
4. Rare Tetratoma (1+ germ layer; from totipotent gonads)
   - eg. benign cystic teratoma

Question 4

How do you name a benign tumour?

Answer 4

Name of cell origin + morphological characteristics + -oma

Question 5

How do you name a malignant tumour?

Answer 5

Name of origin of cell + morphological characteristics +

a) mesenchymal: -sarcoma
b) epithelial: -carcinoma

Question 6

What suffix do you use for mesenchymal (stromal) tumour arising from

1. adipose tissue
2. fibrous/connective
3. bone
4. cartilage

Answer 6

1. lip-
2. fibr-
3. oste-
4. chondr-

Question 7

What suffix do you use for epithelial tumour arising from

1. glandular epithelium
2. stratified squamous epithelium

Answer 7

1. Aden-

2. papill-

Question 8

Name 5 behavioural differences in a malignant tumour compared to a benign one

(Hint: comment on growth, spread, metastasis, vessels, speed of growth, shape, state of differentiation, mitotic rate)

Answer 8

1. Growth: expand and infiltrate
2. Spread: does not remain localise; detatched and breach BM
3. Metastasis: spread through lymph node and blood stream
4. can induce angiogenesis instead of taking up local blood supply
5. speed of growth: fast growing
6. state of dx: poorly differentiated
7. shape: non-encapsulated and irregularly shaped
8. mitotic rate: high mitotic rate

Question 9

What does growth rate of a tumour cell depend on?

Answer 9

1. doubling time of tumour
2. fraction of tumour cells that are actively dividing
3. rate which tumour is she/lost (necrotic centre/maturation)
4. extent of differentiation

Question 10

Describe the process of metastasis

Answer 10

vascularization (increase VEGF) > cells dtach from basement membrane > BM degraded (increase in BM proteases) > invasion into ECM > INTRAVASTION into local vessels > circulate > cells adhere to vessels wall > EXTRAVASTION (leave vessels) and migrate into local tissue > 2ary tumour formed

Question 11

What does grading of tumour mean?

Answer 11

Refers to degree of tumor cell (un)differentiation (anaplasia)

(higher grade=more dedifferentiated)

Relate to how ABNORMAL the cells look

Growth rate

**some cancers have their own grading scales-> gleason score for prostate cancer

Question 12

What is the staging of tumours?

Answer 12

TNM staging

1. Tumour size
2. Nodes
3. Metastasis

Question 13

What do you call syndromes that arises as a result of malignant tumour, but not directly caused by it?

Name 1 example

Answer 13

Paraneoplastic syndromes

1. Cushing syndrome

(Ant.) pituitary tumour > increase ACTH (Adrenocorticotropic hormone) > excess cortisol

Question 14

Name 1 neurological paraneoplastic syndrome

Answer 14

Myasthenia gravis

Thymoma (Thymus)~ 15 % of MG patients

weakness of voluntary muscles, diaphragmatic weakness

Tumour > B-cells affected > Auto-immune response (anti-AChR secretion) > normal cell of CNS do not function properly

Question 15

What are the sentinel node?

Answer 15

hypothetical direst lymph node/group of nodes that a cancer ‘drain’/ metastasize into

In TMN staging (M!)

Question 16

What is a misnomer, and name 4 misnomers

Answer 16

Irregularly named tumours
-oma is usually for benign
but in this case, it is referring to malignant tumours

1. hepatoma: MALIGNANT liver tumour
2. melanoma: Malig. skin
3. seminoma: Malig. testicular
4. lymphoma: Malig. lymphocytes

Question 17

What are the 4 categories of paraneoplastic syndromes?

Answer 17

1. endocrine
2. neurological
3. dermatologic and rheumatologic
4. haematologic