Neoplasms 1 Flashcards Preview

ESA 2- Mechanisms of Disease > Neoplasms 1 > Flashcards

Flashcards in Neoplasms 1 Deck (71)
Loading flashcards...
1
Q

What is a neoplasm?

A

An abnormal growth of cells that persists after the initial stimulus is response

2
Q

What must be true for a neoplasm to grow without continuation of the stimulus?

A

Some degree of autonomous growth

3
Q

What is a malignant neoplasm?

A

A neoplasm that invades the surrounding tissue with the potential to spread to a distant site

4
Q

Is hyperplasia reversible?

A

Yes

5
Q

What causes neoplasia?

A

Genetic alterations

6
Q

It neoplasia reversible?

A

No

7
Q

What is a tumour?

A

Any clinically detectable lump or swelling

8
Q

Is a neoplasm a tumour?

A

Yes, but just one type

9
Q

What is a cancer?

A

Any malignant neoplasm

10
Q

What is a metastasis?

A

A malignant neoplasm that has spread from its original site to a new non-contiguous site

11
Q

What must be true of the spread of a malignant neoplasm?

A

It cannot be due to direct spread, it must have some sort of transport mechanism

12
Q

What is the primary site?

A

The original location of the tumour

13
Q

What are the places a cancer has spread to called?

A

Secondary sites

14
Q

What is dysplasia?

A

A pre-neoplastic alteration in which cells show disordered tissue organisation

15
Q

Why is dysplasia not neoplastic?

A

Because the change is reversible

16
Q

What can dysplasia lead to?

A

Neoplasia

17
Q

What is the difference between benign and malignant neoplasms?

A

They show different behaviour

18
Q

What behaviour do benign neoplasms show?

A

They remain confined to their site of origin, and do not produce metastases

19
Q

Are benign neoplasms symptomatic?

A

They may or may not be, depending on location

20
Q

When may benign neoplasms cause symptoms?

A

If at a critical site, for example a small space

21
Q

What do malignant neoplasms have the potential to do?

A

Metastasise

22
Q

What is the problem with malignant neoplasms metastasising?

A

There is an ever increasing tumour burden, the tumour spreads to make new tumours, which then have the potential to make new tumours too

23
Q

What do benign tumours do?

A

Push and squash

24
Q

What do malignant tumours do?

A

Invade and destroy

25
Q

How do benign tumours appear to the naked eye?

A

They grow in a confined local area and so have a pushing outer margin

26
Q

How do malignant tumours appear to the naked eye?

A

They have an irregular, jagged outer margin and may show areas of necrosis and ulceration (if on surface)

27
Q

Why do malignant tumours show areas of necrosis?

A

Often, bits of tumour are growing faster than the blood supply, so undergo ischaemic death

28
Q

Why do malignant tumours cause ulceration?

A

They cause a break in the surface

29
Q

What do neoplasms show under the microscope?

A

Varying degrees of differentiation

30
Q

How do benign tumours appear under the microscope?

A

They have cells that closely resemble the parent tissue, i.e. they are well differentiated

31
Q

How do malignant neoplasms appear under the microscope?

A

They range from well to poorly differentiated

32
Q

What are cells that have no resemblance to any tissue called?

A

Anaplastic

33
Q

What happens to cells with worsening differentiation?

A

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

34
Q

What does an increase in nuclear size reflect?

A

A change in chromosomes

35
Q

What is increased nucleur staining known as?

A

Hyperchromasia

36
Q

What is a variation in size and shape of nuclear staining called?

A

Pleomorphism

37
Q

How do clinicians indicate differentiation?

A

In grades, with high grade being poorly differentiated

38
Q

What does dysplasia represent?

A

Altered differentiation

39
Q

What indicates worsening differentiation?

A

Mild, moderate and severe dysplasia

40
Q

What is neoplasia caused by?

A

Accumulated mutations in somatic cells

41
Q

What are mutations caused by?

A

Initiators and promoters

42
Q

What are initiators?

A

Mutagenic agents

43
Q

What do promoters cause?

A

Cell proliferation

44
Q

What do initiators and promotes result in, in combination?

A

An expanded, monoclonal population of mutant cells

45
Q

What are the main initiators?

A

Chemicals
Infections
Radiation

46
Q

Can chemicals, infections and radiation act as promoters?

A

Some can

47
Q

How can mutations be obtained in some neoplasms?

A

Inherited, rather than from an external mutagenic agent

48
Q

How does a neoplasm emerge from a monoclonal population?

A

Through a process called progression

49
Q

What is progression characterised by?

A

Accumulation of yet more mutations

50
Q

When is a collection of cells monoclonal?

A

If they all originated from a single founding cell

51
Q

Where does evidence that neoplasms are monoclonal come from?

A

The study of the X-linked gene for the enzyme glucose-6-phosphate dehydrogenase (G6PD) in tumour tissue in women

52
Q

How does the G6PD gene provide evidence that neoplasms are monoclonal?

A

The gene has several alleles encoding different isoenzymes. Early in female embryogenesis, one allele is randomly inactivated in each cell (lyonisation). In heterozygous women that happen to have one allele encoding a heat stable isoenzyme and one heat lable isoenzyme, normal tissue will be a patchwork of each type. However, neoplastic tissues only express on isoenzyme indicating a monoclonal group of cells

53
Q

What do genetic alterations affect?

A

Proto-oncogenes and tumour supressor genes

54
Q

What happens to proto-oncogenes that causes neoplasms?

A

They become abnormally activated

55
Q

What are proto-oncogenes called when they are activated?

A

Oncogenes

56
Q

What do tumour suppressor genes normally do?

A

Suppress neoplasm formation

57
Q

What happens to tumour suppressor genes that causes neoplasms?

A

They become inactivated

58
Q

What does the organised system for naming neoplasms take into account?

A

A neoplasms site of origin, wether it is benign or malignant, the type of tissue the tumour forms and sometimes the gross morphology (e.g. a cyst or papilloma_

59
Q

What do benign neoplasms end in?

A

NAME?

60
Q

What do malignant neoplasms end in?

A

-carcinoma if its epithelial
-sarcoma if its a stromal malignant neoplasm

61
Q

What % of malignant tumours are epithelial?

A

90%

62
Q

What can carcinomas be?

A

In situ
Invasive

63
Q

What is meant by a tumour being in situ?

A

There is no invasion through the basement membrane

64
Q

What is meant by a tumour being invasive?

A

It has penetrated through the basement membrane

65
Q

What is leukaemia?

A

A malignant neoplasm of blood-forming cells arising in the bone marrow

66
Q

What are lymphomas?

A

Malignant neoplasms of lymphocytes, mainly affecting lymph nodes

67
Q

What is myeloma?

A

A malignant neoplasm of plasma cells

68
Q

What do germ cells neoplasms arise from?

A

Pluripotent cells, mainly in the testis or ovary

69
Q

What do neuroendocrine tumours arise from?

A

Cells distributed throughout the body

70
Q

Who do -blastomas mainly occur in?

A

Children

71
Q

What are -blastomas formed from?

A

Immature precursor cells