MoD - Neoplasia Flashcards
What makes a neoplasm malignant?
A neoplasm that invades surrounding tissue with the potential to spread to different sites.
What is the definition of neoplasia?
NEW GROWTH
An abnormal growth of cells that persist after the initial stimulus is removed
What is a tumour?
And detectable lump or swelling
What is a cancer?
Any malignant neoplasm
What is metastasis?
A malignant neoplasm that has spread from its original (primary) site to its new (secondary) site.
What is dysplasia?
Pre neoplastic alteration in which cells show disordered tissue organisation.
What are the features of a benign tumour?
They remain confined to their site of origin (don’t produce metastasis)
They grow in a confined area so have a pushing outer margin
Microscopically closely resemble parent tissue, well differentiated
What are the features of a malignant tumour?
These have the potential to metastasise
Irregular outer margin and shape which shows necrosis and ulceration
Microscopically range from well to poorly differentiated
Increased nuclear staining (hyperchromasia)
What is the anaplastic view of cells and in which type of tumour is this seen?
This is cells with no resemblance to tissue with worsening differentiation
Occurs in malignant neoplasia
What is the cause of neoplasia?
Accumulation of mutations in somatic cells
Caused by initiators and promotors (chemicals, infections and radiation)
These cause expanded monoclonal population of mutant cells
This progresses into a neoplasm
How do we know a tumour is monoclonal?
Study of the G6PD gene
This gene has several encoding isoenzyme
In embryogenesis one allele is switched off so in normal tissues there is an isoenzme patchwork
Whist in neoplasm this is ONE isoenzyme
What does genetics have an influence on?
Affects proto-oncogenes and tumour suppressor genes
What does a benign tumour end in?
-oma
What does a malignant tumour end in?
- carcinoma (epithelia)
- sarcoma (stromal)
What is the difference between in-situ carcinomas and invasive ones?
In-situ - no invasion of the BM
Invasive - penetrated BM
