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 pregnancy – the cervix opens up and the columnar epithelium of the endocervical canal is exposed to the acidic uterine fluids 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, NO goblet cells
Intestinal metaplasia – goblet cells begin to appear as well as columnar epithelium
State some features of cancer that are seen in dysplasia.
Large nuclei (and hyperchromatic) Increased mitoses Abnormal mitoses Increased nucleo-cytoplasmic ratio Loss of architectural orientation Loss of uniformity of individual cells
(some of the histological features of malignancy are present)
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 has a high risk of progression to cancer
High grade, darker nuclei
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 LEIOMYOMAS e.g 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 pituitary
If they secrete something dangerous , e.g insulinoma
If they get infected , e.g bladder infection from obstruction of ureter
If they bleed, e.g stomach
If they rupture e.g liver adenoma
If they become twisted (TORTS),e.g ovarian cyst can twist and cut off own blood supply
What are the features of malignant tumours?
Invade surrounding tissues Metastasize They also have no capsule (not always), Well or poorly differentiated (usually poorly), 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
Adenoma – of glandular epithelium
Define carcinoma.
Malignant tumour derived from the epithelium
What are the different types of carcinoma?
Basal cell carcinoma
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
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 peripheral blood
Define lymphoma.
Malignant tumour of lymphocytes (usually) in lymph nodes
Define teratoma.
A tumour derived from germ cells, which has the potential to develop into tumours of all three germ layers
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 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 in the TNM staging system?
Grading – how well differentiated the cancer is
Staging – how far the cancer has spread
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
Give example of where dysplasia is commonly seen?
Cervix, HPV
Colon, Ulcerative Colitis
Stomach, P. anaemia
Give an example of a teratoma
Dermoid cysts
Give an example of a hamartoma
Bile duct hamartoma
Define neoplasia
An abnormal autonomous proliferation of cells that is unresponsive to normal growth control mechanisms.
Define dysplasia
the presence of cells of an abnormal type within a tissue, which may signify a stage preceding the development of cancer
