S8) Introduction to Neoplasia Flashcards

1
Q

What is a neoplasm?

A

A neoplasm is an abnormal growth of cells that persists after the initial stimulus is removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are malignant neoplasms?

A

A malignant neoplasm is an abnormal growth of cells that persists after the initial stimulus is removed and invades surrounding tissue, potentially spreading to distant sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a tumour?

A

A tumour is any clinically detectable lump or swelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the relationship between the following terms:

  • Neoplasm
  • Cancer
  • Metastasis
A
  • Neoplasm: one type of tumour
  • Cancer: any malignant neoplasm
  • A metastasis: a malignant neoplasm that has spread from its original site to a new non-contiguous site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is dysplasia?

A

- Dysplasia is a pre-neoplastic alteration in which cells show disordered tissue organisation

  • It is not neoplastic because the change is reversible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain how benign and malignant neoplasms show different behaviour

A

- Benign neoplasms remain confined to their site of origin and do not produce metastases

- Malignant neoplasms have the potential to metastasise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Explain how benign and malignant neoplasms appear different to the naked eye

A
  • Benign tumours grow in a confined local area and so have a pushing outer margin (rarely dangerous)

- Malignant tumours have an irregular outer margin and shape and may show areas of necrosis and ulceration, if on a surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the range of differentiation observed in malignant and benign neoplams respectively

A
  • A benign neoplasm has cells that closely resemble the parent tissue, i.e. they are well differentiated

- Malignant neoplasms range from well to poorly differentiated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are anaplastic cells?

A

Anaplastic cells are neoplastic cells with no resemblance to any tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe what happens to neoplastic cells with worsening differentiation

A
  • Increases nuclear:cytoplasmic ratio
  • Increased nuclear staining (hyperchromasia)
  • More mitotic figures
  • Increasing variation in size and shape of cells and nuclei (pleomorphism)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is meant by the term grade?

A

Clinicians use the term grade to indicate differentiation e.g. high grade means poorly differentiated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain how dysplasia can describe different degrees of differentiation

A
  • Dysplasia also represents altered differentiation
  • Mild, moderate and severe dysplasia indicates worsening differentiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What causes neoplasia?

A

Neoplasia is caused by accumulated mutations in somatic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain how mutations in neoplastic cells are caused by initiators and promoters

A

The mutations are caused by initiators (mutagenic agents) and promoters, which cause cell proliferation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the result of the combined efforts of intiators and promoters?

A

A combination of initiators and promoters results in an expanded, monoclonal population of mutant cells:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the different types of initiators and/or sources of mutation in neoplastic cells

A
  • Main initiatiors: chemicals, infections, radiation (some also act as promoters)
  • In some neoplasms, mutations can be inherited rather than from an external mutagenic agent
17
Q

What is progression?

A

Progression is the process through which a neoplasm emerges from its monoclonal population, characterised by the accumulation of yet more mutations

18
Q

What are monoclonal cells?

A

Monoclonal cells are a collection of cells which all originate from a single founding cell e.g. blood cells

19
Q

In four steps, explain how we know that neoplasms are monoclonal

A

⇒ An X-linked gene for the enzyme G6PD in tumour tissue from women has several alleles encoding different isoenzymes

⇒ In early female embryogenesis, one allele is randomly inactivated in each cell (lyonisation)

⇒ In heterozygous women, normal tissues will be patchwork of each type of isoenzyme (heat labile, heat stabile)

⇒ However, neoplastic tissues only express one isoenzyme (monoclonal)

20
Q

Which types of gene are affected by genetic alterations?

A

Genetic alterations affect proto-oncogenes and tumour suppressor genes

21
Q

Describe the genetic alterations which occur to proto-oncogenes and tumour suppressor genes

A
  • Proto-oncogenes become abnormally activated (become oncogenes), favouring neoplasm formation
  • Tumour suppressor genes, which normally suppress neoplasm formation, become inactivated
22
Q

How does one name benign and malignant neoplasms respectively?

A
  • Benign neoplasms end in –oma
  • Malignant neoplasms end in –carcinoma if it is an epithelial malignant neoplasm (90%)
  • Malignant neoplasms end in –sarcoma if it is a stromal malignant neoplasm
23
Q

In terms of invasion, what are the different types of carcinomas?

A
  • In-situ carcinomas: no invasion through epithelial basement membrane

- Invasive carcinomas: penetrated through basement membrane

24
Q

How does one classify epithelial benign neoplasms?

A

- Stratified squamous – squamous papilloma (any tumour with finger-like projections) e.g. skin, buccal mucosa

- Transitional – transitional cell papilloma e.g. bladder mucosa

- Glandular – adenoma e.g. adenomatous polyp of the colon

25
Q

How does one classify epithelial malignant neoplasms?

A
  • Stratified squamous – squamous cell carcinoma e.g. skin, larynx, oesophagus, lung

- Transitional – transitional cell carcinoma e.g. bladder, ureters

- Glandular – adenocarcinoma e.g. stomach, colon, lung, prostate, breast, pancreas, oesphagus

- Other – basal cell carcinoma e.g. skin

26
Q

Name the benign connective tissue neoplasms occurring in the following tissue structures:

  • Smooth muscle
  • Fibrous tissue
  • Bone
  • Cartilage
A

- Smooth muscle – leiomyoma

- Fibrous tissue – fibroma

- Bone – osteoma

- Cartilage – chondroma

27
Q

Name the benign connective tissue neoplasms occurring in the following tissue structures:

  • Fat
  • Nerve
  • Nerve sheath
  • Glial cells
A
  • Fat – lipoma
  • Nerve – neuroma
  • Nerve sheath – neurofibroma
  • Glial cells – glioma
28
Q

Name the malignant connective tissue neoplasms occurring in the following tissue structures:

  • Smooth muscle
  • Fibrous tissue
  • Bone
A

- Smooth muscle – leiomyosarcoma

- Fibrous tissue – fibrosarcoma

- Bone – osteosarcoma

29
Q

Name the malignant connective tissue neoplasms occurring in the following tissue structures:

  • Cartilage
  • Fat
  • Glial cells
A
  • Cartilage – chondrosarcoma
  • Fat – liposarcoma
  • Glial cells – malignant glioma
30
Q

Lymphoid & haematopoietic neoplasms are all regarded as malignant.

Explain how they are named

A
  • Lymphoid neoplasms are called lymphomas and occur in lymphoid tissue, usually in lymph nodes e.g. Hodgkins Disease & Non Hodgkins lymphoma
  • Haematopoietic neoplasms are called acute and chronic leukaemias, which occur in bone marrow, then abnormal cells enter blood
31
Q

What are lymphomas?

A

Lymphomas are malignant neoplasms of lymphocytes, mainly affecting lymph nodes

32
Q

What are leukaemias?

A

Leukaemias are malignant neoplasms of blood-forming cells arising in the bone marrow

33
Q

What are myelomas?

A

Myelomas are malignant neoplasms of plasma cells

34
Q

How do germ cell neoplasms arise?

A

Germ cell neoplasms arise from pluripotent cells, mainly in the testis or ovary

35
Q

Identify some examples of germ cell neoplasms

A

- Testis: malignant teratoma, seminoma (malignant)

- Ovary: benign teratoma (dermoid cyst)

36
Q

How do neuroendocrine tumours arise?

A

Neuroendocrine tumours arise from cells distributed throughout the body

37
Q

Provide some examples of neuroendocrine tumours

A
  • Carcinoid tumours (various organs)
  • Phaeochromocytoma (adrenal)
  • Small cell carcinoma (bronchus)
38
Q

What are blastomas?

A

Blastomas are malignant neoplasms which occur mainly in children and are formed from immature precursor cells e.g. nephroblastoma