Cancer Flashcards
What is a tumour?
Define the term neoplasm + the terms benign and malignant
Define the term cancer
Tumour = any kind of mass forming lesion. May be neoplastic, hamartomatous or inflammatory
Neoplasm: the autonomous growth of tissue which have escape normal constraints on cell proliferation
Neoplasms may be either benign or malignant
Benign - remain localised
Malignant - invade locally and/or spread to distant sites
Cancer = malignant neoplasm
Under what circumstances do benign tumours kill?
Define the term hamartoma
Benign tumours can kill, usually based on their location e.g. the brain
Hamartomas: localised benign overgrowths of one or more mature cell types e.g. in the lung
They represent architectural but not cytological abnormalities
E.g. lung harmatomas are composed of cartilage and bronchial tissue
What are heterotopias?
What are the classifications of neoplasms based on?
What does the stem chondro mean?
What does the suffix oma mean?
What does the suffix sarcoma mean?
Heterotopias = normal tissue being found in parts of the body where they are not normally present.
E.g. pancreas in the wall of the large intestine
The primary description of a neoplasm is based on the cell origin, secondary description is whether it is benign or malignant.
Chondro = derived from cartilage Oma = benign tumour Sarcoma = malignant (soft tissue) tumour
What are teratomas?
What are some malignant tumours w the suffix oma?
Teratomas = tumours derived from germ cells and can contain tissue from all three for 3 germ cell layers
May contain mature / an or mature tissue and cancers.
- lymphoma
- melanoma
- hepatoma (liver cell cancer)
- teratoma (not all)
What are the differences between benign and malignant tumours?
- invasion
- metastasis
- differentiation
- growth pattern
What is invasion describing? What does this distinguish?
What is metastasis?
Invasion = direct extension into the adjacent connective tissue and/or other structures. This is what distinguishes dysplasia/carcinoma in situ from cancer
Metastasis = spread via blood vessels etc to other parts of the body
-all malignant tumours have the capacity to metastasise although they may be diagnosed before they have done so
What does the differentiation stage of the tumour refer to?
What are differences between the nuclei and mitosis patterns between tumour cells and normal cells?
What is nuclear pleomorphism?
Differentiation stage of the tumour refers to how much the cells of the tumour resemble the cells of the tissue it is derived from
Tumour cells have larger nuclei; therefore have a higher nuclear-cytoplasmic ratio. Tumour cells also have more mitoses than normal tissue. They may have abnormal mitoses (e.g. tripolar) and marked nuclear pleomorphism.
Nuclear pleomorphism: variability I’m nuclear size and shape
What are the differences between cancerous cells and normal cells?
Cancerous cells have:
- large, variably shaped nuclei
- many dividing cells; disorganised arrangement
- variation in size and shape
- loss of normal features
What does the looking at the growth pattern of a tumour cell entail?
Compare the growth pattern of a tumour cell to a normal cell
Looking at the Growth pattern of a tumour entails comparing how much the architecture of the tumour resembles the architecture of the tissue it’s derived from.
Tumours have less well defined architecture than the tissue they are derived from
What is the Gleason grading system?
The Gleason grading system is used to evaluate/grade prostate cancer cells obtained by needle biopsy. Each cell assigned a number from 1-5. 5 being most abnormal. Scores of the two most common cell types are added up, generating a score from 2-10. Higher grade = more aggressive cancer.
Benign tumours may become malignant.
What are the 5 routes via which tumours spread?
- Direct extension
- Haematogenous
- Lymphatic
- Transcoelomic
- Perineural
What is direct extension of a tumour associated with?
What types of proliferation does this include?
Direct extension is associated with a stromal response to the tumour.
Includes fibroblastic proliferation (‘desmoplastic response’), vascular proliferation (angiogenesis) and an immune response.
What haematogenous spread of tumour cells mean?
What types of vessels are usually invaded?
What types of cancers metastasise first via the haematogenous route?
- spread via blood vessels
- the blood vessels usually invaded are the venules and capillaries because they have thinner walls
- most sarcomas metastasise first via the blood vessels.
What is the pattern of lymphatic spread dictated by?
What types of cancers metastasise first via the lymphatics?
The pattern of lymphatic spread is dictated by the normal lymphatic drainage of the organ in question.
Most epithelial cancers metastasise first via the lymphatics.
What does transcoelomic spread of tumour cells entail?
Transcoelomic spread is via seeding of body cavities.
The most common e.g.s of this are the pleural cavities (intrathoracic cancers) and peritoneal cavities (intra-abdominal cancers).
What is perineural spread of cancers?
How do we assess tumour spread?
Spread of tumour cells via nerves.
We can assess tumour spread:
- clinically
- radiologically
- pathologically
What is the TNM system?
Define the terms grade and stage when referring to tumours
TNM system is used to describe tumour spread stage, the details are diff for each type of cancer.
T = tumour: the tumour size or extent of local invasion N = Nodes: number of lymph nodes involved M = metastases: presence of distant metastases
Grade = how differentiated is the tumour
Stage = how far has the tumour spread?
-> stage is more important than grade in terms of cancer prognosis
