Pathology Week 8 E Flashcards
(33 cards)
Define Tumour
An abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells and serving no physiological function
Define neoplasm
Is an abnormal mass of cells that exhibits uncontrolled proliferation and that persist after cessation of the stimulus that produced it
Define Cancer
An uncontrolled proliferation of the cells that express varying degrees of fidelity to their precursor
What are parenchyma?
The actual tumour themselves
They reflect the growth pattern and synthetic activity of the parent cell
What is stroma?
The connective tissue framework which surrounds and supports the parenchymal cells. Stroma also contains blood vessels.
What are the 2 functions of stroma?
Mechanical: support for the parenchymal cells
Nutritional: for the parenchymal cells via the blood vessels that are also components of the stroma.
To what size can tumours grow until they need their own blood supply?
1-2mm
What is a desmoplastic reaction?
The process via which growth factors released by the neoplasm stimulate the proliferation of local connective tissue cells
What is angiogenesis?
The process via which growth factors released by the neoplasm stimulate the growth of capillaries from local blood vessels
What is characteristic of scirrhous tumours?
Lots of connective tissue
Very hard
What is characteristic of medullary tumours
Little connective tissue
Soft and fleshy
What shapes can tumours take?
Sessile
Pedunculated
Papillary
Fungating
Ulcerated
Annular
What are the 3 ways that tumours can be classified?
Biological behaviour-how much harm do they cause?
Histogenetic characteristics-from what cell type did they arise?
Degree of differentiation-how closely do they resemble the mature parent cell?
What are the characteristics of benign tumours?
Non Invasive
Slow growth
Histological similar to parent cell
Encapsulated (when growing within solid organs)
Exophytic growth (when growing on surfaces)
Low morbidity
What problems can benign tumours cause?
Pressure on adjacent tissues
Obstruction to the flow of fluids
Hormone production
Anxiety
What are the characteristics of malignant tumours?
Invasive (local and distant spread)
Rapid growth
Variable histological similarity to parent cell
Poorly circumscribed
Central necrosis
Endophytic growth
High morbidity & mortality
What problems can malignant tumours cause?
Pressure on adjacent tissues and organs
Invasion, replacement and destruction of adjacent tissues
Metastasis
Haemorrhage from ulcers etc
Obstruction to flow of air/liquids
Hormone production (ADH, ACTH)
Cachexia other paraneoplastic effects
Anxiety and pain
Thromboembolism
Define differentiation
Differentiation refers to the extent to which neoplastic cells resemble comparable normal cells, both morphologically and functionally
What are the 4 degrees of differentiation?
Well
Moderate
Poorly
Anaplastic
Define anaplasia
Anaplasia is defined as a lack of differentiation
Anaplastic cells have a primitive (embryonic) appearance
What are the characteristics of anapaestic cells?
Pleomorphism (variation in cell size & shape)
Abnormal nuclear morphology (e.g. hyperchromatic, i.e. dark)
Large number of mitoses
Loss of polarity (growth in a disorganised fashion)
A lower graded neoplasm means what?
A higher degree of differentiation= better biologic behaviour
A higher graded neoplasm means what?
A lesser degree of differentiation= consequently a worse biologic behaviour
What is the suffix for benign tumours?
‘oma’
