Lecture 13: Cancer Flashcards
What is a tumour?
Any kind of mass forming a lesion
What is neoplasm?
autonomous (free) growth of tissue which have escaped normal constraints on cell proliferation
How can neoplasms be further categorised?
May be either:
- Benign: remain localised
- Malignant: invade locally and/or spread to distant sites
What are cancers?
malignant neoplasms
True or false: malignant tumours rarely cause death
True - e.g. skin cancers and such don’t cause death even if it has spread
True or false: benign tumours can’t spread so they can’t kill
False - they can kill if in a dangerous location e.g. the brain
What are hamartomas?
localised benign overgrowths of 1 or more mature cell types e.g. lung hamartomas composed of cartilage and bronchial tissue.
they represent architectural not cytological abnormalities i.e. Normal tissues organised abnormally
What are heterotopias?
normal tissues being found in parts of body where they’re normally not present e.g. pancreas in intestine
i.e. Normal tissues in wrong place
How are neoplasms classified?
Primary description = based on cell origin
Secondary description = benign or malignant
How are connective tissue neoplasms classified?
- OMAS = benign
- SARCOMAS = malignant
How are epithelial neoplasms defined?
- OMA = benign
- CARCINOMA = malignant
How are haematological neoplasms defined?
malignant in lymphocytes = lymphoma
malignant in bone marrow = leukaemia
What are teratomas?
tumours derived from germ cells, can contain tissue from all 3 germ cell layers, may contain mature tissue and even cancers
What are some malignant tumours that end with -oma?
Lymphoma
Melanoma
Hepatoma (liver cell cancer)
Teratoma
What are the 4 areas of difference between benign and malignant tumours?
- Invasion
- metastasis
- differentiation
- growth pattern
What is meant by the term invasion (when comparing tumours)?
Means the direct extension into adjacent connective tissue and/or other structures e.g. blood vessels. This is what distinguishes dysplasia/carcinoma in situ from cancer
What is meant by metastasis (when comparing tumours)?
Means spread via blood vessels etc. to other parts of body (all malignant tumours have capacity to metastasise)
What is meant by differentiation (when comparing tumours)?
Means how much do tumour cells resemble derivative tissue
How can tumour cells differ from normal cells?
- larger nuclei (larger nuclear-cytoplasmic ratio)
- more mitoses than normal derivative tissue
- abnormal mitoses e.g. tripolar
- marked nuclear pleomorphism (nuclear size + shape)
What is meant by growth pattern (when comparing tumours)?
Means how much does architecture of tumour resemble derivative tissue architecture.
Do tumours have less or more well defined architecture than the tissue they’re derived from?
Less well defined architecture
What may happen to benign tumours?
They may become malignant
How do tumours spread?
- direct extension
- haematogenous
- lymphatic
- transcoelomic
- perineural
What is meant by direct extension in terms of tumour spread?
Associated w/stromal response to tumour including fibroblastic proliferation (‘desmoplastic response’), vascular proliferation (angiogenesis) and an immune response
