Benign and Malignant disease Flashcards
In adult tissues what is the size of the cell population determined by?
rates of cell proliferation, differentiation and death by apoptosis
what is apoptosis?
pre programmed cell death
what is the balance in tissue homeostasis?
cell division and cell loss
what can alter cell numbers?
rates of stem cell input
cell death by apoptosis
changes in rate of proliferation or differentiation
what controls cell cycle?
stimulators and inhibitors
in terms of cell cycle, what can result in growth?
shortening cell cycle time
recruiting cells from resting or quiescent population
what type of cells are terminally differentiated?
monocytes
what does terminally differentiated mean?
not capable of replicating
what does quiescent mean?
state of dormancy/ inactivity
where would you find quiescent cells that can proliferate when needed?
liver/ kidney
where would you find terminally differentiated cells that may be replaced by new cells arising from stem cells?
epithelia of oral cavity, gut and skin
what act as inhibitors of apoptosis?
growth factors
cell matrix components
viral proteins
what acts as inducers of apoptosis?
withdrawal of GF
loss of matrix attachment
viruses
free radicals
ionising radiation
DNA damage
Fas ligand/ CD95 interaction
what are molecular mediators and regulators of apoptosis?
extrinsic pathway
intrinsic pathway
caspases - cascade
p53
What is the extrinsic pathway in mediation of apoptosis?
death receptors e.g., CD95/ Fas Ligand
what is the intrinsic pathway in molecular mediation of apoptosis?
increased mitochondrial activity
Bcl-2 family
cytochrome c/ Apaf-1
can induce OR inhibit
what can be a result of increased apoptosis?
AIDS
neurodegenerative disorders
reperfusion injury
what can be a result of decreased apoptosis?
neoplasia
auto-immune disease
what is neoplasia?
tumour
what is an increase in cell size?
hypertrophy
where may hypertrophy occur?
skeletal and cardiac muscle
what is an increase in cell number?
hyperplasia
where may hyperplasia occur?
hormonally sensitive organs - endometrium, breast, thyroid
how may you see hyperplasia in the mouth?
hyperplastic responses within epithelium and underlying connective tissue - enlargement of gingival tissues
what is the reduction in cell size by loss of cell substance?
atrophy
what are causes of atrophy?
ageing
lack of use/ stimulation
mechanical
functional
what is the reduction in size of an organ that never fully developed to normal size?
hypoplasia
what is the reversible change in which one adult cell type is replaced by another adult cell type?
metaplasia
when may you find metaplasia?
part of adaptive response to stress
reprogramming of stem cells
e.g., Barett’s oesophagus, Bronchus, Salivary ducts (siametaplasia)
in what way may metaplasia manifest as dysplasia and progress to malignancy?
environmental changes persisting
what disorders of growth and neoplasia are irreversible?
hypoplasia
what is dysplasia in general terms?
abnormal growth
what are examples of types of dysplasia?
congenital hip dysplasia
fibrous dysplasia
epithelial dysplasia
what tissues is dysplasia commonly found in?
squamous e.g., mouth
glandular
what do cells show during pre-invasive dysplasia?
abnormal features that are also seen in cancer cells
these abnormal cells remain within the epithelium
what is neoplasia in general terms?
new growth
what results in neoplasia?
aberration of the normal mechanisms that control cell number
- cell production by cell division
- cell loss by apoptosis
what does monoclonal mean?
the cells in a tumour appear to arise from one parent cell which has undergone a genetic change
why do tumour clones expand?
tumour cells lack the normal control mechanisms
expansion due to uncontrolled profileration
what are the classifications of tomours?
behaviour - benign and malignant
histogenesis
what are features of benign tumours?
histology - resembles tissue of origin
nuclei - small, regular, uniform
mitoses - few, normal
what is pleomorphic adenoma?
common benign salivary gland neoplasm
compare the growth pattern of benign and malignant tumours?
benign - expand and remain localised, well-circumscribed, often encapsulated
malignant - infiltrate locally, metastasize
compare the growth rate of benign and malignant tumours?
benign - slower
malignant - faster
compare the clinical effects of benign and malignant tumours?
benign - local pressure effects; hormone secretions
malignant - local pressure and destruction, inappropriate hormone secretion, distant metastases
compare the treatment of benign and malignant tumours?
benign - local excision
malignant - excision +/- additional therapy
what are the features of malignant tumours?
histology - variable, may differ from tissue of origin
nuclei - larger, pleomorphic
mitoses - increased, often numerous, abnormal forms
what does a pleomorphic adenoma become if it progresses to be malignant?
carcinoma ex pleomorphic adenoma
why must be have a prognosis?
prediction of the probable course and outcome of disease
appropriate treatment and estimate survival
what does a cancer prognosis consist of?
tumour type
tumour grade
tumour stage - histology, clinical, radiological
other parameters - patient, tumour
how does an adenoid cystic carcinoma of salivary gland spread?
perineurally
what disorder can adenoid cystic carcinoma of salivary gland result in?
CNV11 palsy
how is tumour graded?
how well differentiated the tumour cells are
how are tumours staged?
anatomical extent of disease
- clinical
- radiological
- pathological findings
what is used to stage tumours?
TNM classification of malignant tumours
what are the components of the TNM classification of malignant tumours?
T - extent of primary tumour
N - absence or presence and extent of regional lymph node metastasis
M - described the absence or presence of distant metastasis
what is the relation between tumour stage and prognosis?
higher stage = poorer prognosis
