Cell pathology 3 - Cancer Flashcards
Define a tumour
Any kind of mass forming lesion. May be neoplastic, hamartomatous or inflammatory
Define neoplasm
The autonomous growth of tissue which have escaped normal constraints on cell proliferation.
How can neoplasms be classified?
- Benign (remain localised)
- Malignant (invade locally/spread to distant sites)
What are cancers?
Malignant neoplasms
Do malignant tumours always cause death?
No, especially not skin cancers
Can benign tumours kill?
Yes, usually due to their location
What is a hamartoma?
- Localised benign overgrowths of one of more mature cell types e.g. in the lung.
- Represent architectural but not cytological abnormalities.
What are heterotopias?
These are normal tissue being found in parts of the body where they are no normally present.
How are neoplasms classified?
The primary description of a neoplasm is based on the cell origin and the secondary description is whether it is benign or malignant.
What are teratomas?
- These are tumours derived from germ cells and can contain tissue derive from all three for 3 germ cell layers.
- They may contain mature and / or immature tissue and even cancers.
What are suffixes generally in malignant or benign tumours?
Malignant ends in -sarcoma
Benign ends in -oma
Which malignant tumours end in -oma?
- (Malignant) Lymphoma
- (Malignant) Melanoma
- Hepatoma (better called liver cell cancer).
- Teratoma (not all)
List the 4 possible differences between benign and malignant tumours
- Invasion
- Metastasis
- Differentiation
- Growth pattern
What is invasion?
This means direct extension into the adjacent connective tissue and /or other structures e.g. blood vessels.
What is metastasis?
This means spread via blood vessels etc to other parts of the body.
What is differentiation?
This means how much do the cells of the tumour resemble the cells of the tissue it is derived from.
What is the difference in differentiation between malignant and benign tumours?
- Tumour cells have larger nucleus (and nuclear-cytoplasmic ratio) and more mitoses.
- May have abnormal mitoses and marked nuclear pleomorphism (variability in nuclear size and shape).
What is the growth pattern?
This means how much does the architecture of the tumour resembles the architecture of the tissue it is derived from.
How does the growth pattern of tumours differ to normal cells?
Tumours have less well defined architecture than the tissue they are derived from.
Can benign tumours become malignant?
Yes
By which routes to tumours spread?
- Direct extension.
- Haematogenous.
- Lymphatic
- Transcoelomic
- Perineural
What is direct extension?
- This is associated with a stromal response to the tumour.
- This includes fibroblastic proliferation (desmoplastic response), vascular proliferation (angiogenesis) and an immune response.
What is the haematogenous route of tumours spreading?
- This is via blood vessels.
- Usually the venules and capillaries as they have thinner walls.
Where do most sarcomas first metastasise?
Most sarcomas metastasise first via the blood vessels.
What is the lymphatic route of tumours spreading?
- This is lymphatics to lymph nodes and beyond.
- The pattern of spread is dictated by the normal lymphatic drainage of the organ in question.
Where do most epithelial cancers metastasise first?
The lymphatics
What is the transcoelomic route of tumours spreading?
- This is via seeding of body cavities.
- Examples are the pleural cavities (for intrathoracic cancers) and the peritoneal cavities (for intra-abdominal cancers)
What is the perineural route of tumours spreading?
Through nerves
How is tumour spread assessed?
- Clinically
- Radiologically
- Pathologically
What is the TNM system?
- A method of describing tumour spread
- T is the tumour size/extent of local invasion
- N is nodes - the number of lymph nodes involved
- M is metastases - presence of distant metastases
What is the grade and stage in cancer?
Grade is how differentiated the tumour is.
Stage is how far the tumour has spread
Is grade or stage more important in tumour prognosis?
Stage
