1: Cellular Pathology of Cancer Flashcards
Metaplasia
- A reversible change in which one adult cell type (usually epithelial)is replaced by another adult cell type
- Adaptive (e.g. to change in pH, reverts when the circumstances change)
- e.g. columnar epithelium to squamous
Dysplasia
- an abnormal pattern of growth in which some of the cellular and architectural features of malignancy are present
- pre-invasive stage with INTACT BASEMENT MEMBRANE
- this is the step between normal cells and cancerous cells (normal epithelium becomes dysplastic before it becomes cancer)
- increased nucleus-cytoplasmic ratio
- If we can diagnose “cancer” at the stage of dysplasia it is easy to treat and treatment is 100% effective because no spread (INTACT BM)
- loss of architectural orientation
- loss in uniformity of individual cells
- nuclei: hyperchromatic, enlarged
mitotic figures: abundant, abnormal, in places where not usually found
Where is dysplasia common and what causes it?
CERVIX - HPV infection BRONCHUS - Smoking COLON - UC LARYNX - Smoking STOMACH -Pernicious anaemia OESOPHAGUS- Acid reflux
Dysplasia - low grade and high grade
- previously there was also moderate
- low grade: risk of progresion is low, more likely to reverse easily
- high grade: less likely to reverse spontaneously, high risk of progression
- a high grade slide may be darker because the nucleocytoplasmic ratio is higher and the cells appear darker.
Neoplasia, Tumour, Malignancy
An abnormal, autonomous proliferation of cells unresponsive to normal growth control mechanisms
What are the features of benign tumours?
- do not invade do not metastasise
- encapsulated (if you can move the mass around i.e. it is not attached to skin or muscle it is a good sign)
- usually well differentiated
- slowly growing
- normal mitoses
=> the first one is key, it is functional; the first one is absolute, the other ones are just characteristics how we recognise benign tum ours.
Are benign tumours alsways harmless?
NO!
- their location is also very important; also whether they secrete anything.
- i.e. in the Brain
- in the meninges, it may cause hydrocephalus due to blocking of CSF flow between the lateral ventricles and the 3rd ventricle. This is very serious and could kill you.
- i.e. pituitary tumours may cause visual defects as well as secretion of hormones
- Secreting something dangerous: Insulinoma
- can get infected, cause bleeds, rupture, torts
=> adenomas are benign but not necessarily good.
What may make a benign tumour fatal?
- In a dangerous place: meninges, pituitary
- Secretes something dangerous: insulinoma
- Gets infected: bladder
- Bleeds: stomach
- Ruptures: liver adenoma
- Torts (twisted): ovarian cyst
What are characteristics of malignant tumours?
- invade surrounding tissues
- spread to distant sites
- no capsule
- well to poorly differentiated
- rapidly growing
- abnormal mitoses
=> the first 2 are about behaviour. The other 4 are how we recognise them.
What is a metastasis?
- A metastasis is a discontinuous growing colony of tumour cells, at some distance from the primary cancer
- makes local treatment impossible / not enough
- These depend on the lymphatic and vascular drainage of the primary site
- Lymph node involvement has a worse prognosis
Where do testicular cancer metastasise?
- aortic lymph nodes
Benign and malignant tumours are distinguished from each other by all of the following except:
- Degree of differentiation
- Speed of growth
- Capsulation
- Invasiveness
- Site
- Site
Well differentiated tumours are characterised by all of the following, except:
- A small numbers of mitoses.
- Lack of nuclear pleomorphism
- A high nuclear-cytoplasmic ratio.
- Relatively uniform nuclei
- Close resemblance to the corresponding normal tissue
- A high nuclear-cytoplasmic ratio.
What is nuclei polymorphism?
Nuclei look different from one another
What are benign epithelial tumours called?
- Of surface epithelium = PAPILLOMA
(e. g. skin, bladder) - Of glandular epithelium = ADENOMA
(e. g. stomach, thyroid, colon, kidney, pituitary, pancreas)
