Neoplasm Flashcards
(37 cards)
Define malignant neoplasm
An abnormal growth of cells that persists after the initial stimulus is removed which invades surrounding tissue with potential to spread to distant sites
Define neoplasm
Abnormal growth of cells that persists after original stimulus is removed
Define tuumour
A clinically detectable lump or swelling.
Define 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 to which it has spread is a secondary site.
Define dysplasia?
Why is this different to neoplasm?
A pre-neoplastic alteration in which cells show disordered tissue organisation.
It is not neoplastic because the change is reversible.
How do benign and malignant neoplasms differ?
Benign neoplasms remain confined to their site of origin and do not produce metastases. Malignant neoplasms have the potential to metastasise.
Why are benign tumours usually safer?
They grow in a confined local area and so have a pushing outer margin, which limits them making them safer
Why are malignant tumours usually more dangerous?
They have an irregular outer margin (grow faster than vascularisation) and shape and may show areas of necrosis and ulceration (if on a surface).
How do benign and malignant tumours appear histologically?
A benign neoplasm has cells that closely resemble the parent tissue, i.e. they are well differentiated. Malignant neoplasms range from well to poorly differentiated.
What is anaplastic tissue?
Cells with no resemblance to any tissue.
What is nuclear hyperchromasia?
Staining of nucleus (can be used to see increasing nuclear size and nuclear to cytoplasmic ratio)
What is pleomorphism?
Mitotic figures and increasing variation in size and shape of cells and nuclei.
What is a grade?
What is the significance of this clinically?
Grades are used to rate how well differentiated tissues are.
A higher grade means that the tissue is poorly differentiated, therefore there is a shorter prognosis
What are initiators and promoters?
Initiators are mutagenic agents
Promoters cause cell proliferation
What is progression?
When a neoplasm arises from a monoclonal population
How do we know neoplasms are monoclonal?
A collection of cells is monoclonal if they all originated from a single founding cell - G6DP tissue in women (lyonisation - results in neoplastic tissues which are either all paternal or maternal)
What are oncogenes?
Activated proto oncogenes (usually activated abnormally in cancer) favouring neoplasm formation
What role do tumour suppressor genes have?
Tumour suppressor genes, which normally suppress neoplasm formation, become inactivated during neoplasm formation
How do you name benign tumours?
Benign neoplasms ends in –oma.
How do you name malignant tumours?
Malignant tumours end in –carcinoma if it is an epithelial malignant neoplasm, which constitute 90% malignant tumours, or –sarcoma if it is a stromal malignant neoplasm.
What types of carcinoma are there?
Carcinomas can be in-situ (no invasion of epithelial basement membrane) or invasive (penetrated through basement membrane).
What is leukaemia?
Leukaemia is a malignant neoplasm of blood-forming cells arising in the bone marrow.
What are germ line neoplasms?
Germ cell neoplasms arise from pluripotent cells, mainly in the testis or ovary.
What are neuroendocrine tumours?
Neuroendocrine tumours arise from cells distributed throughout the body.
