MoD Flashcards
Define atherosclerosis
The thickening and hardening of the arterial wall as a consequence of atheroma
Define atheroma
The accumulation of intracellular and extracellular lipid in the intima and media of large and medium sized arteries
Define arteriosclerosis
Thickening of walls of arteries and arterioles independently of atheroma e.g. from HTN or DM
Define neoplasm
An abnormal growth of cells that persists after the initial stimulus is removed
What is a malignant neoplasm?
A neoplasm that invades surrounding tissue with the potential to spread to distant sites
Define tumour
Any clinically detectable lump or swelling
Define metastasis
A malignant neoplasm that has spread from its original site to a new non-contiguous site
What is dysplasia?
A preneoplastic alteration in which cells show disordered tissue organisation (reversible)
How do benign neoplasms behave?
Remain confined to site of origin
Do not produce metastases
May become malignant
How do malignant neoplasms behave?
Have the potential to metastasise
Describe the naked eye appearance of a benign tumour
Grow in a confined local area
Pushing rounded outer margin
May be surrounded by a fibrous pseudocapsule
Describe the naked eye appearance of a malignant tumour
Irregular outer margin and shape
May have areas of necrosis (because they grow faster than their blood supply) and/or ulceration
What is the difference between a benign and malignant neoplasm with regard to the degree of differentiation?
Benign - well differentiate, closely resemble parent tissue
Malignant - range from well to poorly differentiated
What are anaplastic cells?
Have no resemblance to any tissue
What features to cells adopt with worsening differentiation?
Increasing nuclear size
Increasing nuclear to cytoplasmic ratio
Nuclear hyperchromasia (increased staining)
More mitotic figures
Pleomorphism - increasing variation in size and shape of cells and nuclei
What is an initiator?
Mutagenic agent
What is a promoter?
Causes cell proliferation
Define monoclonal
All cells originate from a single founding cell
Explain the evidence for neoplasm monoclonality obtained from the study of G6PD enzyme in female tumour tissue
Gene has several alleles encoding different isoenzymes
Early in female embryogenesis one allele is randomly inactivated in each cell (lyonisation)
In heterozygous women who happen to have 1 allele encoding a heat stable isoenzyme and 1 allele encoding a heat labile enzyme, normal tissues will contain a patchwork of each type
Neoplastic tissues only express one isoenzyme so are monoclonal
How are malignant epithelial neoplasms named?
Carcinoma
How are stromal/mesenchymal neoplasms named?
Sarcoma
What is the difference between an in situ and an invasive carcinoma?
In situ - no invasion of epithelial basement membrane
Invasive - penetrates through basement membrane
What is leukaemia?
Malignant neoplasm of blood-forming cells, arising in bone marrow
What is lymphoma?
Malignant neoplasm of lymphocytes, mainly affecting lymph nodes
