Neoplasia Flashcards
What is a neoplasm
An abnormal growth of cells that persists after the initial stimulus is removed
Malignant neoplasm
An abnormal growth of cells that persists after the initial stimulus is removed and invades surrounding tissue with potential to spread to distant sites
What is a tumour
Any clinically detectable lump or swelling
Cancer
Malignant neoplasm
Metastasis
Malignant neoplasm that has spread from its original site to a new non-contigious site
Dysplasia
A pre-neoplastic alteration in which cells show disordered tissue organisation
Not neoplasticism as it is reversible
Why are benign tumours rarely dangerous
Grow in a confined local area and so have a pushing outer margin
Why are malignant tumours dangerous
They have a irregular outer margin and shape and may show areas of necrosis and ulceration
What are anaplastic cells
Cells with no resemblance to any tissue
How do benign tumour look microscopically
Closely resembles the parent tissue- well differentiated
Pleomorphism
With worsening differentiation individual cells have increasing
nuclear size and nuclear to cytoplasmic ratio, increased nuclear
staining (hyperchromasia), more mitotic figures and increasing
variation in size and shape of cells and nuclei
High grade
Poorly differentiated
What causes neoplasia
Accumulated mutations in somatic cells which are caused by initiators
Monoclonal
All the cells of the neoplasm came from the same cell
How to name benign neoplasms
End in -oma
Malignant neoplasms end in
-carcinoma
Epithelial malignant neoplasms end in
-carcinoma
In situ
No invasion through epithelial basement membrane
Invasive
Penetrated through basement membrane
What is leukaemia
Malignant neoplasm of blood-forming cells arising in the bone marrow
Myeloma
Malignant neoplasm of plasma cells
How does metastasis occur
- Grow and invade at primary site
- Enter a transport system and lodge at secondary site
- Grow at the secondary site to form a new tumour- colonisation
What does invasion into surrounding tissue require
Altered adhesion
Stroma proteolysis
Motility
All these things create a carcinoma cell phenotype that appears like a mesenchymal cell so is called a epithelial-to-mesenchymal transition
What does altered adhesion require
Reduction in E-Cadherin expression
Changes in tntegrin expression
Changes in actin cytoskeleton
How can malignant cells transport to distant sites
- Blood vessels via capillaries and ventless
- Lymphatic vessels
- Fluid in body cavities - transcoelomic spread
Colonisation
MALIGNANT CELLS MUST GROW AT A SECONDARY SITE TO FORM A CLINICAL
METASTASIS: AT A SECONDARY SITE MALIGNANT CELLS MUST GROW
Micrometases
Surviving microscopic deposits that fail to grow
What determines the site of secondary neoplasm
- regional draining of blood, lymph or coelom in fluid
- the seed and soil phenomenon
How do carcinoma typically spread
lymphatics
How do sarcomas usually spread
Blood stream
Common sites of blood borne metastasis
Lung
Bone
Liver
Brain
Which neoplasms frequently spread to bone
Breast Bronchus Kidney Thyroid Prostate
Local effects of neoplasm are due to..
Direct invasion and destruction of normal tissue
Ulceration at a surface leading to bleeding
Compression of adjacent structures and blocking tubes and orifices
Systemic effects of neoplasm
Increasing tumour burden- parasitic effecr on host
Secreted cytokines cause reduced appetite and weight loss, malaise, immunosuppresion, thrombosis
micro-metastises
clinically undetectable groups of malignant cells. These micro-metastases can start to regrow after a period of time, which is what causes an apparently cured patient to relapse. This is also the reason why patients with cancer cannot donate their organs
lymphomas
malignant neoplasms of lymphocytes mainly affecting Lymph nodes
stromal malignant neoplasm
-sarcoma
