L61, L62: Neoplasia Flashcards

1
Q

Definition of neoplasia

A

Abnormal mass of tissue, growth EXCEEDS and UNCOORDINATED compared with normal tissues and PERSISTS in the same excessive manner after cessation of the stimuli which evoked the change

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

Neoplasia vs hyperplasia

A

Hyperplasia:

  1. Occurs under influence of physiological factor e.g. growth factors and ceases after removal of such factors
  2. Similar to normal tissue but occasionally occur alongside hypertrophy

Neoplasia:

  1. Uncoordinated proliferation of cells despite the absence/removal of stimuli
  2. Characterised by dysplasia (abnormality of development of cells) or anaplasia (loss of cellular differentiation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is malignant neoplasm

A

Neoplasm that shows

  1. Invasion into surround tissues
  2. Metastasise to distant sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
Benign vs malignant neoplasms
In terms of
1. Mode of growth
2. Rate of growth
3. Gross appearance
4. Microscopic appearance
5. Metastasis
6. Clinical effects
7. Outcome
A

Benign vs Malignant:
1. Mode of growth:
Expansive, limited by BM
Infiltrative, Invasion beyond BM

  1. Rate of growth
    Slow and may cease
    Rapid and outgrow blood supply —> necrosis
  2. Gross appearance:
    Circumscribed/encapsulated
    Poorly defined margins
  3. Microscopic appearance
    Well-differentiated, resemblance of tissue of origin (morphologically and functionally)
    Low NC ratio
    Normochromatic nuclei
    Absent or scanty mitotic figures
    Maintained polarity (apical-basal polarity)

VS

Pleomorphism (variation in size and shape)
High NC ratio / prominent nucleoli
Hyperchromatic nuclei
Abnormal and increased mitosis (tripolar/multipolar spindles)
Loss of polarity

  1. Metastasis:
    Absent vs present
  2. Clinical effects:
    Mechanical/hormonal
    Mechanical/hormonal & destructive and systemic effects caused by cytokines
  3. Outcome:
    Rarely fatal vs usually fatal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name for benign and malignant tumours of epithelium

A

Benign: Papilloma
Malignant: Carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name for benign and malignant tumours of glandular epithelium

A

Benign: Adenoma
Malignant: Adenocarcinoma

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

Definition of dysplasia

A
  • Disorderly proliferation of cells
  • Loss in uniformity and polarity
  • Mild, moderate and severe
  • A process which can ultimately lead to pre-invasive neoplasm (carcinoma-in-situ).
  • Mild to moderate dysplasia may be reversible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Intrinsic control mechanisms of tumour growth

A
  1. Proliferation rate
  2. Death rate (apoptosis)
  3. Differentiation rate (become mature, non-dividing cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Extrinsic control mechanisms of tumour growth

A
  1. Immune response
  2. Blood and nutrient supply
  3. Hormonal and growth factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

10 common biological properties of cancer

A
  1. Self-sufficiency in growth signals
  2. Insensitivity to anti-growth signals
  3. Evading apoptosis
  4. Evading immune destruction
  5. Tissue invasion and metastasis
  6. Limitless replicative potential
  7. Sustained angiogenesis
  8. Genome instability and mutation
  9. Deregulating cellular metabolism
  10. Tumour-promoting inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

5 types of spread of a tumour

A
  1. Local invasion (type 4 collagenase cleaves the collagen)
  2. Metastasis (via lymphatics and blood)
  3. Transcoelomic spread (penetrating surfaces such as peritoneal, pleural, pericardial/subarachnoid space)
  4. Perineural spread
  5. Implantation (by surgical instruments)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Definition of metastasis

A

Discontinuous spread of a tumour / formation of new sites of growth at non-contiguous site
Some cancer cells have organ trophism

Common sites of metastasis (記 LLLBB):

  1. LN
  2. Lungs (Breast, Colon)
  3. Liver (Esophageal, Stomach, Pancreatic, Lung, Breast, Kidney, Skin)
  4. Bone (TBLPK: Thyroid, Breast, Lung, Prostate, Kidney)
  5. Brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

4 effects of tumour

A
  1. Local effects
  2. Non-specific systemic effects
  3. Hormonal effects
  4. Paraneoplastic syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Definition of clonality of tumours

A

Tumours cells arising from mitotic division of the same single somatic cell

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

Definition of heterogeneity of tumours

A

Tumour cells which have distinct morphological and phenotypic profiles with different characteristics such as ability to invade, metastasise etc.

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

Describe the process of carcinogenesis

A
  1. Mutations within the DNA of a cell
  2. Clonal expansion of cell
  3. Cells able to develop heterogeneity
  4. Overcome selection pressure
  5. Accumulation of different mutations/heterogeneity
  6. No longer responds to regulatory signals
  7. Better adapt at survival, growth, invasion, metastasis
  8. Tumour become more aggressive and less responsive to treatment
17
Q

Cause of growth autonomy

A
  1. Activation of proto-oncogene —> oncogene (Dominant gene)
    - Code for growth factors etc.
    - Promoter insertion
    - Adjacent enhancer insertion
    - Chromosomal rearrangement
    - Point mutation
  2. Inhibition of tumour suppressor gene —> anti-oncogene (Recessive gene)
    - Inheritable, e.g. loss of 1 Rb allele in familial retinoblastoma
    - Deletion
    - Point mutation
    - Promoter methylation
  3. Alteration of genes regulating apoptosis
18
Q

Cause of Carcinogenesis

A
  1. Hereditary factors
    - Autosomal dominant cancer
    - Autosomal recessive cancer
  2. Ethnical
  3. Chemical
    - long latent period
    - great individual variation due to SNPs which gives varying degree of susceptibility
    - Initiator (electrophilic and mutagenic, causing rapid irreversible DNA changes e.g. alkylation agents, aromatic hydrocarbons)
    - Promoter (stimulate proliferation of cell without altering DNA e.g. estrogen hormone)
  4. Radiation (Initiator)
  5. Viruses (viral DNA integration —> viral oncoprotein which modify function of cellular proteins)
    - Epstein-barr virus: Nasopharyngeal carcinoma, Burkitt lymphoma
    - Human papilloma virus: Cervical cancer
    - Hepatitis B virus: Hepatocellular carcinoma
  6. Hormonal and drugs
  7. Chronic irritation
  8. Immunodeficiency
19
Q

Examples of autosomal dominant cancer

A
  1. Familial adenomatous polyposis (FAP)
    - germline mutation in adenomatous polyposis coli (APC) gene in chromosome 5
    - APC gene: tumour suppressor gene
    - 2nd copy of APC gene if inactivated will lead to excessive cell proliferation
  2. Hereditary non-polyposis colon cancer syndrome (HNPCC)
    - DNA mismatch repair gene mutation
    - failure to repair replication errors in microsatellites
    - somatic mutation inactivate the remaining copy of MMR gene —> inability to repair
20
Q

Example of autosomal recessive cancer

A

Xeroderma pigmentosa

21
Q

Most common tumours in adult and children

A

Adult: carcinoma (84%)
Children: leukaemia/ lymphoma (46%), CNS malignancy

22
Q

Most common cancer in Hong Kong (male and female)

A

Male:
Lung, colorectal, liver, stomach, prostate
Female:
Lung, colorectal, breast, liver, pancreatic