Cellular pathology of cancer Flashcards
What is metaplasia?
A reversible change in which one adult cell type (usually epithelium) is replaced with another cell type
What is a common example of pathological metaplasia and what happens?
Barrett’s oesophagus- Gastro-oesophageal reflux causes the oesophageal epithelium to change from squamous to columnar
What is a common 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
What is gastric metaplasia?
Stratified squamous to simple columnar
What is intestinal metaplasia?
Goblet cells appear
What is dysplasia?
An abnormal pattern of growth in which some of the cellular and architectural features of malignancy are present
What is dysplasia a common sign of?
Cells that are on the road to cancer
What stage is dysplasia?
Pre-invasive with an intact basement membrane
What are the cell features of cancer?
Large nuclei Increased mitoses Abnormal mitoses Increased nucleo-cytoplasmic ratio Loss of architectural orientation Loss of uniformity of individual cells Hyperchromatic and enlarged Mitotic figures are abundant, abnormal and in places where they aren't usually found
Where is dysplasia common and why?
Cervix- HPV infection Bronchus- smoking Colon- ulcerative colitis Larynx- smoking Stomach- pernicious anaemia Oesophagus- acid reflux
What does normal cellular maturation look like (in the cervix)?
Cells are very compact at the bottom and then become more and more spaced out towards the lumen
What does abnormal cell maturation look like?
Compact cells with dark dense nuclei on the surface- these cells are normally seen further down
What is the difference between low and high grade dysplasia?
Both show changes of dysplasia but changes are more severe in high grade and there is a greater risk of progression to cancer- the nuclei are bigger and nucleo-cytoplasmic ratio is higher in high grade
What is neoplasia?
Any new growth, belong or malignant
What is a tumour?
Swelling (nasal polyps are considered tumours)
What is malignancy?
An abnormal autonomous proliferation of cells, unresponsive to normal growth control mechanisms
What are the features of a benign tumour?
Don't invade or metastasise Encapsulated- compressed capsule Usually well differentiated Slowly growing Normal mitoses
What is the exception to benign tumours being encapsulated?
Fibroids (leiomyoma) in the uterus
When do benign tumours become fatal?
In a dangerous location- meninges and pituitary Secrete something dangerous- insulinoma Gets infected- bladder Bleeds- stomach Ruptures- liver adenoma Torts- ovarian cyst
What are the features of a malignant tumour?
They invade surrounding tissues Spread to distant sites No capsule Well to poorly differentiated Rapidly growing Abnormal mitoses
What is a metastasis?
A discontinuous growing colony of tumour cells at some distance from the primary cancer
What do the sites of metastasis depend on?
Lymphatic and vascular drainage of the primary site
Give an example of the sites of metastasis being affected by lymphatic and vascular drainage?
Pancreas is drained by splenic vein which then goes via the hepatic portal vein to the liver so pancreatic carcinomas tend to present with liver metastases
What is the effect of lymph node involvement?
It worsens the prognosis
What is a papilloma?
Benign tumour of surface epithelium
What is a benign tumour of glandular epithelium called?
Adenoma
Where are papillomas found?
Skin and bladder
Where are adenomas found?
Stomach, thyroid, colon, pituitary and pancreas
What is a carcinoma?
A malignant tumour derived from epithelium
What are the different types of carcinoma?
Squamous cell carcinoma
Adenocarcinoma
Transitional cell carcinomas
Basal cell carcinoma
What are carcinomas classified by?
The tissues that they come from
What is a benign soft tissue tumour of bone called?
Osteoma
What is a lipoma?
Benign tumour of fat
What is a benign tumour of smooth muscle called?
Leiomyoma
What is a sarcoma?
Malignant tumour derived from connective tissue (mesenchymal) cells
What makes up the prefix of a sarcoma?
The site of the tumour
What is a sarcoma of cartilage called?
Chondrosarcoma
What is a sarcoma of striated muscle called?
Rhabdomyosarcoma
What is a leiomyosarcoma?
Smooth muscle sarcoma
What is leukaemia?
Malignant tumour of bone marrow derived cells in which circulate in the blood
What is a lymphoma?
Malignant tumour of lymphocytes in lymph nodes
What is teratoma?
A tumour derived from germ cells which has the potential to develop into tumours of all three germ cell layers
What are the three germ cell layers?
Ectoderm, mesoderm and endoderm
What is the difference between gonadal teratomas in males and females?
In males, they are almost all malignant
In females, they are mostly benign
What is haemartoma?
Localised growth of cells and tissues native to the organ- tissues that are present are appropriate for that particular part of the body but the way that they are architecturally arranged is inappropriate
What population are haemartomas common in?
Children
How are tumours classified?
They are graded and staged
What is the grading of a tumour?
How well differentiated they are
What is the staging of a tumour?
How far they’ve spread
What is more important between grading and staging?
Staging
What needs to be done when a tumour is found?
You need to find out if it is primary or secondary- this is done histologically and looking for evidence for normal function
What is the specific grading system for breast cancer?
Nottingham scoring system
What is the specific grading system for prostate cancer?
Gleason classification
What are tumours that show little or no differentiation described as?
Anaplastic
