11. What Is Neoplasia Flashcards
What is the definition of a neoplasm?
An abnormal growth of cells that persist after the initial stimulus is removed.
What is the definition of a 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. A neoplasm is just one type of tumour.
What is a cancer?
Any malignant neoplasm.
What is a metastasis?
A malignant neoplasm that has spread from its original site to a new non-contiguous site. The original location is the primary site, and the place it has spread to is the secondary site.
What is dysplasia? Why is it not neoplastic?
A pre-neoplastic alteration in which cells show disordered tissue recognition due to altered differentiation.
Not neoplastic as the change is reversible.
What is the difference in behaviour between a benign neoplasm and a malignant neoplasm?
Benign - remains confined to site of origin and does not produce metastases.
Malignant - have potential to metastasise.
What can been seen to the naked eye with benign neoplasms and malignant neoplasms?
Benign - pushing outer margin.
Malignant - irregular outer margin and sharp. May show areas of necrosis and ulceration (if on epithelium).
What are anaplastic cells?
Cells with no resemblance to any tissue.
What is the difference between the cells seen under a microscope in benign neoplasia and malignant neoplasia?
Benign - cells closely resemble parent tissue, well differentiated.
Malignant - range from well to poorly differentiated.
What is seen in an individual cell with worsening differentiation?
Increasing nuclear size. Increasing nuclear to cytoplasmic ratio. Increased nuclear staining. More mitotic figures. Increasing variation in size and shape of cells and nuclei.
What term is used by clinicians to indicate differentiation?
Grade. Higher the grade the more poorly differentiated. Tends to correlate with more aggressive tumours.
What do initiators do?
Causes a mutation.
What do promotors do?
Cause cell proliferation
What do initiators and promotors result in in combination?
An expanded monoclonal (all originating from the same cell) population of mutant cells.
What is progression?
The process through which a neoplasm emerges from a monoclonal population, by the accumulation of yet more mutations.
In what combination do initiators and promotors need to be given to cause a neoplasia?
An initiator to cause the mutation, and then a promotor for a prolonged period of time to cause cell proliferation and increase the number of cells with the mutation.
What are the 3 main initiators? What is one other way that the mutations can come from?
Chemicals, infections, radiation (some also act as promotors). Inherited.
What is a neoplasm ending in -oma?
Benign
What is a neoplasm ending in -carcinoma?
Epithelial malignant neoplasm (90% of malignant tumours)
What is a neoplasm ending in -sarcoma?
Stromal malignant neoplasm
What is an in-situ carcinoma?
No invasion through epithelial basement membrane.
What is an invasive carcinoma?
Has penetrated through basement membrane.
What is leukaemia?
Malignant neoplasm of blood-forming cells arising in the bone marrow.
