Cellular pathology of cancer Flashcards
(29 cards)
What is metaplasia?
A reversible change in which one adult cell type is replaced by another adult cell type
Give an example of metaplasia
- Gastric Metaplasia (stratified squamous to simple columnar)
- Intestinal metaplasia (goblet cells appear)
What are the 2 types of metaplasia?
Pathological and physiological
Give an example of pathological metaplasia
Gastro-oesophageal reflux causes the oesophageal epithelium to change from squamous to columnar (Barrett’s oesophagus)
Give an example of physiological metaplasia
In pregnancy the cervix opens up and the columnar epithelium of the endocervical canal is exposed to the acidic uterine fluids making it become squamous
When the cervix closes up again, the cell type changes back to normal (metaplasia is reversible)
What is dysplasia?
Pre-invasive stage of cancer development
- abnormal pattern of growth in which some cellular and architectural features of malignancy are present
What is found in dysplasia?
- intact basement membrane
- increased nucleo-cytoplasmic ratio
- loss of architectural orientation
- hyperchromatic, enlarged nuclei
- abundant mitotic figures in abnormal locations too
What are the features of cells in cancer?
- Large nuclei
- Increased and abnormal mitoses
- Increased nucleo-cytoplasmic ratio (nuclei bigger than normal)
What is dysplasia used for?
To screen for cancer before individuals develop cancer - cancer is a multi step process and there are stages in between
Where is dysplasia common?
Cervix – HPV infection
Bronchi – Smoking (pseudostratified columnar -> squamous)
Colon – UC associated with IBD
Layrnx– Smoking
Stomach – Pernicious anaemia (chronic stomach inflammation)
Oesophagus– Acid reflux (Barrett’s oesophagus)
What is high grade and low grade dysplasia?
Difference between the two?
Low grade - unlikely to go on to cancer
High grade - very likely to develop into cancer. Changes are more severe in high-grade dysplasia. The nuclei are bigger and the nucleo-cytoplasmic ratio is higher.
What is malignancy?
An abnormal, autonomous proliferation of cells unresponsive to normal growth control mechanisms. These cells grow on their own.
What is neoplasia?
Any new growth, benign or malignant
What is a tumour
swelling
What is the difference between benign and malignant?
Benign:
- Do not invade (so do not metastasise)
- Encapsulated
- Usually well differentiated
- Slowly growing
- Normal mitoses
When can benign tumours be fatal?
- If they are in a dangerous place: a benign tumour in the meninges
- Secretes something dangerous: insulinoma – leads to hypoglycaemic episodes
- Gets infected
- Bleeds
- Ruptures: liver adenoma (can cause massive haemoperitoneum)
- Torts (twisted): ovarian cyst -> infarction due to lost blood supply (ischaemic necrosis)
What is metastasis?
A discontinuous growing colony of tumour cells, at some distance from the primary cancer. Cells can break off and embolise around the body.
How are benign epithelial tumours named?
papilloma or adenoma
papilloma: surface epithelium e.g. skin
adenoma: glandular epithelium e.g. stomach
How are malignant epithelial tumours named?
CARCINOMA
- if from squamous cells then squamous cell carcinoma
- if from glandular epithelium then adenocarcinoma
- if from transitional epithelium then transitional cell carcinoma
- basal cell carcinoma
How are benign soft tissue tumours named?
- osteoma: benign bone tumour
- lipoma: benign fat tumour
- leiomyoma: benign smooth muscle tumour
How are malignant soft tissue tumours named?
Derived from connective tissue (mesenchymal cells)
SARCOMA
- prefix is the site of the tumour e.g. fat would be liposarcoma
- bone: osteosarcoma
- cartilage: chondrosarcoma
- striated muscle: rhabdomyosarcoma
- smooth m: leiomyosarcoma
- nerve sheath: malignant peripheral nerve sheath tumour
What are leukaemias and lymphomas?
Tumour of WBCs
leukaemia: malignant tumour of bone marrow derived cells which circulate in blood
lymphoma: malignant tumour of lymphocytes in lymph nodes
What is a teratoma?
A teratoma is a tumour derived from germ cells, which have the potential to develop into tumours of all three germ cell layers: ectoderm, mesoderm and endoderm
- have mutiple components
- gonadal teratomas in males are almost always malignant
- females almost always bengin and have teeth/hair
What is a hamartoma?
- Mostly benign but risk of malignancy
- Localised overgrowth of cells and tissues native to the organ
- Cells are mature but architecturally abnormal
- Common in children, and should stop growing when they stop
- E.g. bile duct hamartomas, bronchial hamartomas
- E.g. may have many bile ducts, weird shapes, arranged abnormally etc
- Normal cells, but architecture is abnormal
