Benign and malignant disease Flashcards
what is the size of a cell population determined by?
rates of cell proliferation, differentiation, and death by apoptosis
what is cell division balances by?
cell loss
how may cell numbers be altered?
- rates of stem cell input
- cell death due to apoptosis
- rate of proliferation/ differentiation
what is regeneration of cell population controlled by?
chemical factors in the micro-environment of the cell - stimulators and inhibitors
how may growth occur?
shortening cell cycle time
recruiting cells from resting or quiescent population
what type of cells cant replicate and give an example?
terminally differentiated cells - monocytes
what does quiescent mean?
dormant
what type of cells are normally quiescent but can proliferate when needed to?
differentiated cells in liver/ kidney
what type of cells are short-lives and incapable of replicating but may be replaced by new cells arising from stem cells?
terminally differentiated mature cells in the epithelia of the oral cavity, gut and skin
what is apoptosis?
pre-programmed cell death
give examples of inhibitors?
growth factors
cell matrix components
viral proteins
give examples of inducers?
withdrawal of GFs
loss of matrix attachment
viruses
free radicals
ionising radiation
DNA damage
Fas ligand/ CD95 interaction
what are molecular mediators and regulators of the extrinsic pathway for apoptosis?
death receptors - CD95/ Fas ligand
what are molecular mediators and regulators of the intrinsic pathway for apoptosis?
increased mitochondrial permeability
Bcl-2 family
Cytpchrome c/Apaf-1
what are examples of diseases that increase apoptosis?
AIDS
Neurodegenerative disorders
Reperfusion injury
what are examples of diseases that decrease apoptosis?
neoplasia
autoimmune disease
what are the disorders of growth and neoplasia?
hypertrophy
hyperplasia
atrophy
hypoplasia
metaplasia
dysplasia
what is hypertrophy and what cells does it affect?
increase cell size
- muscle, skeletal or cardiac
what is hyperplasia and what cells does it effect?
increase cell number
- hormonally sensitive organs (endometrium, thyroid, breast
what is atrophy and what cells does it affect?
reduction cell size (loss of cell substance)
- thyroglossal duct
what is hypoplasia?
reduction size of an organ that never fully developed to normal size
- developmental defect
what is metaplasia and what does it affect?
one cell replaced by another cell - reversible
adaptive response to stress
mesenchymal tissues
what disorder of growth is irreversible?
hypoplasia
what is dysplasia?
abormal growth
how does neoplasia occur?
aberration of normal mechanisms that control cell number
are most tumour cells monoclonal?
yes
what does monoclonal mean?
all cells arise from one parent cell that has undergone a genetic change
what is the growth pattern for benign tumours?
expand remain localised, typically well circumscribes and often encapsulated.
what is the growth rate for benign tumours?
slow
what are the clinical effects of benign tumours?
local pressure effects; hormone secretions
what is the treatment for benign tumours?
local excision
what is the histology of a benign tumour?
resembles tissue of origin
what are the nuclei of benign tumours like?
small, regular and uniform
what are mitoses of benign tumours?
few and normal
what is a pleomorphic adenoma?
common benign salivary gland tumour
what is the growth pattern of malignant tumours?
infiltrate locally then metastasize
what is the growth rate for malignant tumours?
fast
what are the clinical effects of malignant tumours?
local pressure and destruction
what is the treatment for malignant tumours?
excision and additional therapy sometimes
what is the histology of malignant tumours?
variable and many differ from tissue of origin
what are the nuclei of malignant tumours like?
larger and pleomorphic
describe mitoses of malignant tumours?
increased, often numerous and abnormal forms
what does a pleomorphic adenoma become when it progresses to malignancy?
carcinoma ex pleomorphic adenoma
classify covering epithelia when benign and malignant
b - papilloma
m - carcinoma
classify glandular epithelia when benign and malignant
b - adenoma
m - adenocarcinoma
what is a prognosis?
prediction of the probable course and outcome of disease
what are the 4 factors of a prognosis?
tumour type
tumour grade
tumour stage
other parameters
what are tumour types?
aggressive and indolent
how are tumours graded?
well-differentiated and poorly differentiated
what are features of well differentiated tumour cells?
squamous with ‘prickles’ and keratinisation
what is used to stage tumours?
TNM classification of malignant tumours
what does TNM stand for when staging tumours?
T - extent of primary tumour
N - absence/ presence and extent of regional lymph node metastasis
M - absence/ presence of distance metastasis
how are tumours staged?
each component of TNM given a number - higher the number the more extensive the disease
e.g., T1N0M0
usually no M in pathological staging
