Cellular Pathology of Cancer Flashcards
Define Metaplasia.
A reversible change in which one adult cell type (usually epithelial) is replaced by another adult cell type
Give two examples of metaplasia, one pathological and one physiological.
Barrett’s Oesophagus – gastro-oesophageal reflux can change the stratified squamous epithelium of the distal oesophagus to simple columnar Cervix during puberty – the cervix opens up and the columnar epithelium of the endocervical canal is exposed to the acidic ph of the vagina making it squamous
What are the two types of metaplasia that can take place in Barrett’s Oesophagus?
Gastric metaplasia – stratified squamous to simple columnar Intestinal metaplasia – goblet cells begin to appear
State some features of cancer that are seen in dysplasia.
- Large, hyperchromatic nucleus
- Increased mitoses
- Abnormal mitoses
- Increased nucleo-cytoplasmic ratio
- Loss of architectural orientation
- Loss of uniformity of individual cells
What is the difference between low and high-grade dysplasia?
They both show changes of dysplasia but the changes are more severe in high-grade dysplasia High-grade: High risk of progression to cancer Less chance of reversal
What are the main features of benign tumours that separate them from malignant tumours?
They do not metastasise They do not invade They also are usually encapsulated (except for fibroids in the uterus) slow growing normal mitoses
Under what conditions can benign tumours be dangerous?
If they are in a dangerous location e.g. csf network leading to hydrocephalus If they secrete something dangerous If they get infected If they bleed If they rupture If they become twisted
What are the features of malignant tumours?
Invade surrounding tissues Spread to distant sites They also have no capsule can be well or poorly differentiated, rapidly growing abnormal mitoses
Define metastasis.
A discontinuous growing colony of tumour cells, at some distance from the primary cancer
What are the two different types of benign epithelial tumour?
Papilloma – of the surface epithelium e.g. skin, bladder Adenoma – of glandular epithelium e.g. stomach, thyroid, colon, kidney, etc
Define carcinoma.
Malignant tumour derived from the epithelium
What are the different types of carcinoma?
Basal cell carcinoma - skin Squamous cell carcinoma Transitional cell carcinoma (transitional epithelium is found in the bladder) Adenocarcinoma
State some different types of benign soft tissue tumour.
Osteoma –bone Lipoma - fat Leiomyoma – smooth muscle Chondroma - cartilage
Define sarcoma.
Malignant tumour derived from connective tissue (mesenchymal) cells
What are the names given to malignant tumours of striated muscle, smooth muscle and the nerve sheath?
Striated muscle – rhabdomyosarcoma Smooth muscle – leiomyosarcoma Nerve sheath – Malignant peripheral nerve sheath tumour
Define leukaemia.
Malignant tumour of bone marrow derived cells, which circulate in the blood
Define lymphoma.
Malignant tumour of lymphocytes usually in lymph nodes
Tissue based, commomly in lymph nodes, spleen and tonsil
Define teratoma.
A tumour derived from germ cells, which has the potential to develop into tumours of all three germ layers: ectoderm, mesoderm, endoderm
What is an important difference between teratomas in men compared to women?
Gonadal teratomas in men are almost always malignant Gonadal teratomas in women are almost always benign
Define hamartoma.
Localised overgrowth of cells and tissue native to the organ In other words, the cells and tissues present are cytologically appropriate for that particular location but their structural organisation is inappropriate
Which group of the population is hamartoma common in?
It is common in children and the hamartoma usually stops growing when the children stop growing
What is the difference between grading and staging?
Grading – how well differentiated the cancer is Staging – how far the cancer has spread Importance: Staging > Grading
What is meant by the ‘degree of differentiation’?
How much the tumour cells resemble the cells from which they are derived
What are the grading systems for breast and prostate cancer?
Breast –Nottingham scoring system Prostate – Gleason classification
What is the term given to tumours that show little or no differentiation?
Anaplastic
Define 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
Define neoplasia
An abnormal, autonomous proliferation of cells unresponsive to normal growth control mechanisms Can be benign or malignant
What does TNM stand for?
Tumor Node Metastases
