MoD S9 - Neoplasm I Flashcards Preview

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Flashcards in MoD S9 - Neoplasm I Deck (25):
1

Define 'neoplasm'

An abnormal growth of cells that persist after the initial stimulus is removed

2

How does a malignant neoplasm differ from a benign neoplasm?

The malignant neoplasm invades surrounding tissue with potential to spread to distant sites (have the potential to metastasise), benign does not

3

Define 'Tumour'

Give an example of a tumour

A tumour is any clinically detectable lump or swelling

E.g. A neoplasm

4

What is a cancer?

A malignant neoplasm

5

What is a metastasis?

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

The original site is the primary site

The metastasis is a secondary site

6

How does dysplasia relate to neoplasm?

Give a difference between the two

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

Dysplasia is not neoplastic change as it is reversible

7

What are the two major types of tumour?

Non-neoplastic (E.g. Abscess,haematoma)

Neoplastic (benign, malignant)

8

What are the differences in benign and malignant neoplasm to the naked eye?

Benign tumours grow in a confined local area and so have a pushing outer margin (This is why they're so rarely dangerous)

Malignant tumours have an irregular outer margin and shape and show areas of necrosis and ulceration (if on surface)

9

What are the differences in benign and malignant neoplasm under the microscope?

Malignant:
- Neoplasms are well to poorly differentiated
- Increasing nuclear size and nuclear to cytoplasmic ratio
- Nuclear hyperchromasia
- Higher mitotic count, may be abnormal
- Increased size and shape variance of cells and nuclei (pleomorphism)

Benign :
- Neoplasms closely resemble patient's tissue (i.e. well differentiated)
- Minimal pleomorphism
- Lower mitotic count, mitoses are normal

10

What is meant by the term 'anaplastic'?

Where do anaplastic cells occur?

Cells with no resemblance to any tissue are called anaplastic

Occur in malignant neoplasm

11

How is level of differentiation of a tissue rated?

What clinical outcome does differentiation correlate with?

Tissue given a grade G1 to G3

G3 is poorly differentiated, G1 is well differentiated

Higher grade has lower 5 year survival rate

12

What is the cause of neoplasia?

Accumulated mutations in somatic cells

Mutations are caused by:
- Initiators, which are mutagenic agents
- Promoters, which cause cell proliferation

13

What are the main initiators?

Chemicals
Infections
Radiation

Some also act as promoters

14

When promoters and initiators work in tandem on cells what is the result?

An expanded monoclonal population of mutant cells (mutations caused by initiators and promoters)

A neoplasm emerges from this population through a process known as progression, characterised by the accumulation of yet more mutation

15

How do we know neoplasms are monoclonal?

Study of X linked genes for the enzyme glucose-6-phosphate (G6P) dehydrogenase in tumour tissue from women

The gene has several alleles encoding different isoenzymes of the enzyme, In early female embryogenesis one allele is randomly deactivated (lyonisation)

In heterozygous women with one heat labile isoenzyme and one heat stable isoenzyme normal tissues are a patchwork of each type

Neoplastic tissues only express one isoenzyme indicating a monoclonal population

16

What genetic mutations are necessary for neoplasm formation?

How are these genes changed?

Genetic alterations affecting proto-oncogenes and tumour supressor genes

Proto-oncogenes become abnormally activated to form oncogenes that favour neoplasm formation

Tumour suppressor genes become inactivated

Genetic differences must be not be lethal so genetic change can pass onto daughter cells

17

How are neoplasms named to differentiate them?

Benign:
- Neoplasm = -oma

- Epithelial with gland like structure = adenoma

- Epithelial projecting fronds into a lumen = papilloma

Malignant:
- Epithelial neoplasm (90% of cancer) = -carcinoma

*Note* can be in situ or invasive (no invasion or invasion through the basement membrane respectively)

- Stromal neoplasm = -sarcoma

- WBC forming cells = Leukaemia

- Lymphocytes = Lymphoma

- Plasma cells = Myeloma

Both:

- Immature precursor cells = - blastoma

Pluripotent cells = Germ cell neoplasm

Neurological or endocrine tissue = Neuroendocrine

18

Give 3 examples of benign epithelial neoplasms and the cell type that makes them up (if not immediately obvious)

-oma

Squamous papilloma
Transitional cell papilloma
Adenoma (glandular tissue)

19

Give 4 examples of malignant epithelial neoplasms

-carcinoma

Squamous cell carinoma (stratified)
Transitional cell carcinoma
Adenocarcinoma (glandular tissue)
Melanoma (malignant despite suffix)

20

Give 8 examples of benign connective tissue neoplasm and include the tissue each arises from

Smooth muscle - Leiomyoma

Fibrous tissue - Fibroma

Bone - Osteoma

Cartilage - Chondroma

Fat - Lipoma

Nerve - Neuroma

Nerve sheath - Neurofibroma

Glial cells - Glioma

21

Give examples of malignant connective tissue neoplasm and include the tissue each arises from

Smooth muscle - Leiomyosarcoma

Bone - Osteosarcoma

Fibrous tissue - Fibrosarcoma

Cartilage - Chondrosarcoma

Fat - Liposarcoma

Glial cells - Malignant Glioma

22

Give 2 examples of lymphoma

Hodgkin's Disease
Non-Hodgkin's lymphoma

23

Give 3 examples of germ cell neoplasm and the organ from which they arise

Testes:
- Malignant teratoma
- Seminoma (malignant)

Ovary:
- Benign Teratoma (Dermoid cyst)

24

Give 3 examples of neuroendocrine tumours

Carcinoid tumours (various organs)
Phaeochromocytoma (adrenal gland)
Small cell carcinoma of the bronchus

25

Give some of the key differences between neoplastic and normal cells, include the genetic basis for each difference

Self sufficient growth signals:
- HER2 gene amplification

Resistance to anti-growth signals:
- CDKN2A gene deletion

Grow indefinitely:
- Telomerase gene activation

Induce new blood vessels:
- Activation of VEGF expression

Resistance to apoptosis:
- BCL2 gene translocation

Invade and produce metastases:
- Altered E-cadherin expression