Cancer 1: 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
Barrett’s oseophagus - squamous epithelium to columnar epithelium
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
Increased nuclei cytoplasmic ratio as a cancer goes through metaplasia, dysplasia, neoplasia etc - darker
What is typically seen in dysplasia?
- 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 in?
CERVIX - HPV infection BRONCHUS - Smoking COLON - UC (ulcerative colitis) LARYNX - Smoking STOMACH -Pernicious anaemia OESOPHAGUS- Acid reflux
What is the difference between low grade and high grade?
Low grade = risk of progression is slow, more likely to be reversible
High grade = more likely to progress and less likely to be reversible
Define neoplasia?
Tumour, malignancy
An abnormal, autonomous proliferation of cells unresponsive to normal growth control mechanisms
Describe benign tumours
1 ) do not invade local tissue = do not metastasise
encapsulated
usually well differentiated
slowly growing
normal mitosess
When do benign tumours become fatal?
Usually not fatal unless:
- In a dangerous place: meninges, pituitary. Blockage of CSF in the lateral ventricles
- Secretes something dangerous: insulinoma
- Gets infected: bladder
- Bleeds: stomach
- Ruptures: liver adenoma
- Torts (twisted): ovarian cyst = ischaemic death
Describe malignant tumours
- invade surrounding tissues
spread to distant sites no capsule well to poorly differentiated rapidly growing abnormal mitoses
Define metastasis
A metastasis is a discontinuous growing colony of tumour cells, at some distance from the primary cancer
Dependent on lymphatic and vascular drainage of the primary site. Lymph node involvement has a worse prognosis. e.g colon
Tumour in the lateral aspect of the breast –> axillary lymph nodes
Describe benign epithelial tumours
Of the surface of epithelium = PAPILLOMA e.g skin, bladder
Of the glandular epithelum = ADENOMA e.g stomach, thyroid, colon, kidney, pituitary, pancreas
Describe carcinoma
A malignant tumour derived from epithelium
What are the types of carcinomas?
squamous cell
adenocarcinoma
transitional cell (come from the bladder)
basal cell carcinoma
Give an example of a benign soft tissue tumour?
Osteoma
Define sarcoma
A malignant tumour derived from connective tissues (mesenchymal) cells
What are the different types of sarcoma?
Fat = liposarcoma
Bone = osteosarcoma
Cartilage = chondrosarcoma
Muscle:
Striated = Rhabdomyosarcoma
Smooth = Leiomyosarcoma
Nerve sheath = Malignant Peripheral Nerve Sheath TumourDefine Leukaemia
A malignant tumour of the bone marrow derived cells which circulate in the blood
Tumour of white blood cells
Define Lymphoma
A malignant tumour of lymphocytes usually in lymph nodes
Define teratoma
Is a tumour derived from germ cells, which have the potential to develop into tumours of all three germ cell layers
- ectoderm
- mesoderm
- endoderm
What are the difference between male and female gonadal teratomas?
Males = all malignant Females = most are benign
Define hamartoma
Localised overgrowth of cells and tissues native to the organ
Cells are mature (so normal) but architecturally abnormal. They way they are arranged is abnormal.
Common in children, and should stop growing when they do,
e.g. bile duct hamartomas, bronchial hamartomas,
How do you differentiate tumours?
Criteria for assessing differentiation of a malignant tumour:
1) Evidence of normal function still present production of:
keratin,
mucin
bile
hormones
2) Various grading systems - for Ca breast, prostate, colon
3) no differentiation, ANAPLASTIC carcinoma - no idea what it is
Describe the grading of tumours?
The grade of a tumour describes its degree of differentiation. How much does it look like the tissue from which its derived and how much does it do like from the tissue its derived.
What is the stage of a tumour?
The stage describes how far it has spread. Stage is more important than grade in determining prognosis. Its about progression.
High grade tumours tend to be higher stage.
TNM system - Tumour, Node, Metastasis
Stage is more important that grade in determining prognosis
