Cellular pathology Flashcards
Define metaplasia
A reversible change in which one adult cell type (usually epithelial) is replaced by another adult cell type
Define dysplasia
An abnormal pattern of growth in which some of the cellular and architectural features of malignancy are present
Define neoplasia
Any new growth, benign or malignant
Define tumour
Swelling
Define malignancy
An abnormal, autonomous proliferation of cells, unresponsive to normal growth control mechanisms
Define hamartoma
Localised overgrowth of cells and tissues native to the organ
Define carcinoma
A malignant tumour derived from epithelium
Define sarcoma
A malignant tumour derived from connective tissue (mesenchymal) cells
Define teratoma
A tumour derived from germ cells, which has the potential to develop into tumours of all three germ cell layers
Define lymphoma
A malignant tumour of lymphocytes (usually) in lymph nodes
Define leukaemia
A malignant tumour of bone marrow derived cells which circulate in the blood
Define metastasis
A discontinuous growing colony of tumour cells, at some distance from the primary cancer
What features distinguish benign tumours from malignant tumours?
Benign:
- do not invade
- do not metastasise
- are encapsulated
- usually well differentiated
- slowly growing
- normal mitoses
Malignant = all opposite
Define carcinogen
A substance or agent that causes cancer
What morphological features indicate differentiation of a tumour?
- Evidence of normal function, e.g. production of keratin, bile, mucin, hormones etc. = unlikely to be high grade
If no evidence = possibly high grade or even anaplastic - Mitoses important, particularly when abnormal - some tumours require standard mitotic count
