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Year 2 EMS MoD > Tumour characteristics > Flashcards

Flashcards in Tumour characteristics Deck (66):
1

What is cancer?

The uncontrolled growth of cells, which can invade and spread to distant sites.

2

What is a tumour?

An abnormal swelling.

3

What is a neoplasm?

Lesion resulting from autonomous growth of cells that persists in the absence of the initiating stimulus.

4

What is histogenesis?

The differentiation of cells into specialised tissues/organs during growth from undifferentiated cells (germ layers).

5

What is the histogenic classification of tumours that arise from epithelial cells?

Carcinomas.

6

What is the histogenic classification of tumours that arise from connective tissue?

Sarcomas.

7

What is the histogenic classification of tumours that arise from lymphoid/haematopoietic organs?

Lymphomas / leukaemias.

8

What was the epidemiology of cancer worldwide in 2008?

12.7 million new cases.
7.6 million deaths.

-expected to increase

9

What causes geographical variation in specific cancers? (2)

-Exposure to environmental carcinogens
-Screening programmes

10

How has the incidence of cancer changed since 1975?

Steady increase in incidence, slower rate now due to awareness/screening.

11

How has the mortality of cancer changed since 1975?

Overall decrease.

12

What are the most common cancers in males? (3)

-Prostate
-Lung
-Colon / rectum

13

What are the most common cancers in females? (3)

-Breast
-Lung
-Colon / rectum

14

How are tumours characterised? (4)

-Differentiation
-Rate of growth
-Local invasion
-Metastasis

15

Do malignant tumour tumour grow faster than benign tumours?

Not necessarily - many exceptions.
-rapidly-growing malignant tumours tens to be lethal faster

16

What is differentiation?

The extent that neoplastic cells resemble normal parenchymal cells.
-both morphologically and functionally

17

How do benign and malignant tumours differ in terms of differentiation?

*BENIGN - well-differentiated (resemble parenchymal cells), mitoses rare
*MALIGNANT - wide-range of differentiation, most have morphological change

18

What does morphology mean in terms of tumours?

Shape/structure of cells.

19

What is aanaplasia?

Poor cellular differentiation, don't resemble normal.
-usually malignant

20

What are the main morphological changes that occur in tumours? (4)

-Neoplasm
-Abnormal nuclear morphology
-Mitoses
-Loss of polarity

21

What is pleomorphism?

Variation in size/shape of cells and their nuclei.

22

List some examples of abnormal nuclear morphology. (4)

-Nuclei too large for cell
-Variable nuclear shape
-Clumped chromatin distribution
-Hyperchromatin

23

What is the nuclear to cytoplasmic ratio of most cells?

1:4 to 1:6.
-can >> 1:1 in tumour cells

24

What is mitoses?

A method of cell division, indication proliferation.
-seen in normal tissues with high turnover rate
-seen in malignancy

25

What are the abnormal mitotic processes seen in malignancy?

Tripolar, Quadripolar, etc.

26

What is loss of polarity?

-Orientation of cells disturbed
-Disorganised growth
-nuclei move to bottom

27

What does well-differentiated mean?

Closely resembles normal tissue of origin.
-little/no anaplasia
-benign (occasionally malignant)

28

What does poorly differentiated mean?

Little resemblance to normal tissue of origin.
-very anaplastic

29

What does undifferentiated / anaplastic mean?

Very poor differentiation, cannot be identified by morphology alone.
-molecular techniques required

30

What is grade a measure of?

How well differentiated a tumour is.
-1/low = well differentiated
-3/high - poorly differentiated

31

What is stage a measure of?

The severity and prognosis of a disease.

32

What does better differentiation lead to?

Better retention of normal function.

33

What are the main features of endocrine tumours? (3)

-Benign and well-differentiated
-Often secrete hormones characteristic of origin
-Increased hormone levels can be used for diagnosis

34

What is local invasion?

When tumours spread to healthy tissue immediately surrounding them.

35

What are the invasive features of benign tumours? (2)

-Localised to site of origin
-No capacity to infiltrate / invade / metastasise

36

What are the invasive features of cancerous tumours? (3)

-Infiltration
-Invasion
-Destruction

37

What is encapsulation in relation to benign tumours?

Rim of compressed fibrous tissue surrounds benign tumours.
-ECM is deposited by stromal cells activated by hypoxia

38

What is the tissue plane of a benign tumour?

Moveable, easily palpable and easily excised.
-due to capsule

39

What often surrounds malignant tumours?

Pseudo-encapsulation.
-slow-growing, rows of cells penetrate margin

40

Why is surgical resection of malignant tumours often difficult?

Often penetrate organ surfaces and invade.
- requires resection of adjacent normal tissue

41

What is metastasis?

The spread of tumour to sites physically discontinuous with primary tumour.
-indicates malignancy

42

Do benign tumours metastasise?

No.

43

What proportion of non-skin malignancies have metastasised at diagnosis?

30%.

44

What are the general features of tumours that have metastasised? (4)

-Lack of differentiation
-Local invasion
-Rapid growth
-Large size

45

What are the main pathways for metastasis? (3)

-Direct seeding
-Lymphatic spread
-Haematogenous spread

46

What are the general features of metastasis due to direct seeding?

Neoplasm penetrates an open field, without physical barriers (e.g. peritoneal cavity, joint spaces).
-can remain confined to surfaces without penetrating

47

Give an example of a malignancy in the abdomen that spreads via direct seeding?

Pseudomyxoma peritonei.
-often spreads before penetrating bowel wall

48

What are the main features of lymphatic spread?

-Tumours spread within lymphatic vessels
-Follows route of lymphatic drainage

49

How does breast cancer spread, and where does it normally spread to first?

Via the lymphatic system.
-axillary nodes first

50

What is the sentinel node?

The first lymph node that receives flow from the primary tumour.

51

How are sentinel nodes identified?

Injection of tracers / coloured dyes.

52

What are regional lymph nodes?

A lymph node that drains lymph from the region around the tumour.

53

How are regional lymph nodes used to prevent further tumour spread?

Tumour cells stop within regional nodes and can be destroyed by a tumour-specific immune response.

54

What type of tumour is haematogenous spread more common in?

Sarcomas.
-also seen in carcinomas

55

What type of blood vessels are more easily penetrated by tumours?

Veins.
-thinner walls

56

Where do tumour often metastasise to via haematogenous spread?

First encountered capillary bed.
-liver (portal) and lungs (caval) are most common

57

How does the rate of growth differ between malignant and benign tumours?

Benign tumours tend to be slow-growing, malignant tend to be faster.
-variable

58

What is a stroma?

Connective tissue framework that neoplastic cells (and organs) are embedded in.

59

What 3 things does a stroma provide?

-Mechanical support
-Intercellular signalling
-Nutrition

60

What is a desmoplastic reaction?

Fibrous stroma formation around the tumour due to induction of connective tissue fibroblast proliferation by growth factors.

61

What do stroma surrounding tumours contain?

-Cancer-associated fibroblasts
-Myofibroblasts
-Blood vessels
-Lymphocytic infiltrate

62

What are the main types of clinical complications of tumours? (3)

-Local
-Metabolic
-Due to metastases

63

What are the local clinical complications of tumours?

-Compression (displacement of surrounding structures)
-Destruction (invasion)

64

What is thyrotoxicosis?

Hyperthyroidism.
-well differentiated, large tumour >> increase thyroid hormones

65

What are non-specific metabolic effects of tumours?

-Cachexia (weight loss)
-Warburg effect
-Neuropathies
-Myopathies
-Venous thrombosis

66

What is the Warburg effect?

Cancer cells predominantly produce energy by a high rate of glycolysis followed by lactic acid fermentation.
-increased glucose uptake on scan