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
Adaptive
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
Intestinal metaplasia – goblet cells begin to appear
Define dysplasia
Abnormal growth pattern where some of the cellular and architectural features of malignancy are present. pre-invasive stage with an intact basement membrane
State some features of cancer that are seen in dysplasia.
All in places wouldn’t expect: Large nuclei (and hyperchromatic) Increased mitoses Abnormal mitoses Increased nucleo-cytoplasmic ratio Loss of architectural orientation Loss of uniformity of individual cells
Common sites of dysplasia
Cervix- HPV infection
Oesophagus- acid reflux
Bronchioles- smoking
Stomach- pernicious anaemia
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
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
Slow growing and have normal mitoses
Under what conditions can benign tumours be dangerous?
If they are in a dangerous location - meninges, pituitary
If they secrete something dangerous - insulinoma
If they get infected - bladder
If they bleed - stomach
If they rupture - liver
If they become twisted - ovaries
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 and have 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
How can sarcomas be distinguished for fat bone and cartilage
Fat- liposarcoma
Bone- osteosarcoma
Cartilage- chondrosarcoma
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
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
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
