Neoplasia 1 Flashcards
(22 cards)
What is a tumour?
Swelling (any clinically detectable lump or swelling)
Define neoplasm
An abnormal growth of cells that persists after initial stimulus is removed; ‘new growth’
Define oncology
The study of tumours and neoplasms
Define benign neoplasm
Abnormal growth of cells that is grossly and microscopically innocent, will remain localised and won’t spread to other sites
Define cancer
A malignant neoplasm (colloquial term)
Define malignant neoplasm
Abnormal growth of cells that persists after initial stimulus is removed and invades surrounding tissue with potential to spread
Define metastasis
A malignant neoplasm that has spread from original site to a new non-contiguous site
Define dysplasia
Pre-neoplastic alteration in which cells show disordered tissue organisation; reversible
What are the two types of malignant neoplasm?
1) Primary = original location
2) Secondary = metastasis
What are key characteristics of benign metaplasia?
- Grows in a confined area
- Pushing outer margin
- Rarely dangerous location
- Closely resemble parent tissue (well differentiated)
What are key characteristics of malignant metaplasia?
- Invade and have potential to metastasise
- irregular outer margin and shape
- May have ulcerations and necrosis
- Infiltrative
- Ranges from well to poorly differentiated
Define what an anaplastic cell mean
Cells with no resemblance to any tissue (poorly differentiated)
What are features of worsening differentiation?
- Increasing nuclear size
- Increasing nuclear to cytoplasmic ratio
- Increasing nuclear staining (hyperchromia)
- Increasing mitotic figures
- Abnormal mitotic figures (Mercedes Benz)
- Variation in size and shape of cells and nuclei (polymorphism)
What does a high grade metaplasia mean in terms of differentiation?
Poorly differentiated
-based on Gleason’s pattern (breast cancer)
What type of differentiation would you see in dysplasia?
Ranges from mild, moderate and severe differentiation
-has not breached basement membrane; not yet invasive
What tiggers metaplasia development?
Carcinogens and non-lethal genetic damage
Briefly describe the development of a neoplasm
1) Accumulation of mutations in somatic cells
- mutations from initiators (mutagenic agents)
2) Promoters cause proliferation
3) Tumour formed by clonal expansion of a single cell that has incurred genetic damage
List examples of initiators
- Chemicals e.g. smoking, alcohol, diet and obesity
- Infectious agents e.g. HPV
- Radiation
- Inherited mutations
Define the term monoclonal
A collection of cells that originated from a single founding cell
Define progression in terms of neoplastic development
Accumulation of mutations
What are the genes affected in neoplastic development?
1) Proto-oncogenes = drive proliferation and can activate a new function
2) Tumour suppressor genes = usually stop cell proliferation but mutation leads to failure of growth inhibition
3) Apoptosis regulating gene = mutations result in less cell death and enhanced survival
4) DNA repair genes = impaired ability to recognise and repair non-lethal genetic damage
What are the general rules of naming a neoplasm?
Benign = end in -oma Malignant = end in carcinoma (epithelial) or sarcoma (stromal)
