Introduction to Benign and Malignant Disease Flashcards
Cell proliferation in adult tissues?
In adult tissues size of the cell population is determined by the rates of cell proliferation, differentiation and death by apoptosis
What can cell numbers be altered by?
- By increased or decreases rates of stem cell input.
- By cell death due to apoptosis
- By changes in the rate of proliferation or differentiation
What is the key to regeneration of a cell population?
Control of the cell cycle
Growth of cell can result from..
- Shortening cell cycle time
- Recruiting cell from resting or quiescent population
How many stages in cell division and what are they?
4 stages: 1- G1 2- S 3- G2 4- M
What happens in stage G0?
Cells are quiescent
What is the principle task of cell division cycle?
Replicate DNA and segregate the duplicated chromosomal DNA equally to two daughter cells
Why do cell enter the division cycle?
It is in response to growth stimulation - commitment and restriction in G1
S phase must be completed before what?
Before mitosis begins and vice versa - mechanisms for monitoring progress
What occurs in the checkpoints?
Replication of damaged DNA or segregation of chromosomes must not occur
What is apoptosis?
Programmed cell death
Inhibitors of apoptosis?
- Growth factors
- Cell matrix components
- Viral proteins
Inducers of apoptosis?
- Withdrawal of growth factors
- Loss of matrix attachment
- Viruses
- Free radicals
- Ionising radiation
- DNA damage
Molecular mediator and regulators of apoptosis?
- Extrinsic pathway
- Intrinsic pathway
- Caspases - cascade
- p53
Extrinsic pathway..
Death receptors eg CD95/F as ligand
Intrinsic pathway..
- Increased mitochondrial permeability
- Bcl-2 family
- Can induce or inhibit
Increased apoptosis include:
- AIDS
- Neurodegenerative disorders
- Reprefusion innjury
Decreased apoptosis include:
- Neoplasia
- Auto-immune disease
Disorders of growth and neoplasis…
- Hypertrophy
- Hyperplasia
- Atrophy
- Hypoplasia
- Metaplasia
- Dysplasia
- Neoplasia
What is hypertrophy? and which muscles are related to it?
- An increase in cell size. It is physiological and pathological
Muscles:
- Skeletal
- Cardiac
What is hyperplasia? and which organs are related to it?
- An increase in cell number. It is physiological and pathological.
Enlargement of gingival tissues.
Hormonally sensitive organs:
- Endometrium
- Breast
- Thyroid
What is atrophy?
- Reduction in cell size by loss of cell substances.
It is physiological (thyroglossal duct) and pathological. - Ageing
- Lack of use: Mehcanical or functional
What is hypoplasia?
- Reduced size of an organ that never fully developed to normal size
A developmental defect - eg. Pulmonary hypoplasia
What is Metaplasia?
- Reversible change in which one adult cell type is replaced by another adult cell type
Reprogramming of stem cells - eg. Barrett’s oesophagus, Bronchus, Salivary duct
What can Metaplasia affect?
Affect the mesenchymal tissues
What is dysplasia “Abnormal growth”?
A pre-malignant process and can be identified in many tissues eg. Epithelia.
Degrees of dysplasia?
- Mild
- Moderate
- Severe (carcinoma in situ)
The more severe = risk of progressing to invasive malignancy
What is neoplasia “New growth” result from?
Aberration of normal mechanisms that control cell number
eg:
- Cell production by cell division
- Cell loss by apoptosis
What are the classification of tumours?
- Behaviour
- Histogenesis
Behaviour tumour is split into:
1- Benign
2- Malignant
What are the growth pattern of benign tumour?
- Expand and remain localised.
- Typically well-circumscribed
- Often encapsulated
What is the growth rate of benign tumour?
Slow
What is the clinical effects of benign tumour?
Local pressure effects; hormone secretions
What is the treatment of benign tumour?
Local excision
What is Pleomorphic Adenoma?
A benign salivary gland neoplasm
Histology of benign tumour?
Resembles tissue of origin
Nuclei of benign tumour?
Small, regular and uniform
Mitoses of benign tumour?
Few and normal
What is the growth pattern of malignant tumours?
Infiltrate locally and metastasize
What is the growth rate of malignant tumour?
Fast
What is the clinical effects of malignant tumour?
- Local pressure and destruction.
- Inappropriate hormone secretion
- Distant metastases
What is the treatment of malignant tumour?
- Excision with or without the additional therapy
Histology of malignant tumour?
Variable, many differ from tissue of origin
Nuclei of malignant tumour?
Large and pleomorphic (inconsistent)
Mitoses of malignant tumour?
Increased, often numerous and abnormal forms
Benign and malignant of tissue covering epithelia
Benign: Papilloma
Malignant: Carcinoma
Benign and malignant of tissue Glandular epithelia
Benign: Adenoma
Malignant: Adenocarcinoma
Why do tumour types matter?
Tumour types behave in different ways and therefore the treatment would differ.
Define carcinoma
A cancer arising in the epithelial tissue of the skin or of the lining of the internal organs.
Define sarcoma
a malignant tumour of connective or other non-epithelial tissue
What do tumour type influence?
It influences how patients are investigated, treated and monitored
Aggressive vs indolent tumours?
Aggressive tumours:
- May need to treat before tissue diagnosis
- Risk: benefit to consider at all times
- Aggressive therapy may be necessary and risk are justifiable
- Sometimes appropriate to avoid early active treatment
What does the prognosis of tumour grade depend on?
Depends on the differentiation of tumour.
The more differentiated the tumour - tend to have better prognosis
Tumour stages..
TNM system
T = greatest diameter of tumour, structures invaded N = regional lymph node status M = distant metastasis
High tumour stage results in…
Poor prognosis
