Growth, Differentiation & Tumours Flashcards
Growth definition
Increase in size
Differentiation definition
Process by which cells develop specialised functions or morphology
Tumour differentiation definition
The extent to which tumour cells resemble their normal cell counterparts
Anaplasia
A lack of differentiation
A hallmark of malignant cells
Cells may be pleomorphic, have an abundance of DNA, mitoses, loss of polarity and become gigantic
Neoplasia
New growth, usually of abnormal tissue
Growth is un-coordinated and fast with a lack of contact inhibition
Growth persists even when the stimulus is removed
Causes a benign or malignant tumour
Carcinoma definition
A malignant epithelial tumour
Sarcoma definition
Malignant connective tissue tumours
Benign tumours
Non-invasive and remain localised
Have a slow growth rate and closely resemble the parent tissue
A fibrous capsule separates the tumour from the host tissue
Malignant tumours
Invasive and capable of spreading directly or by metastasis
Have a rapid growth rate and do not closely resemble the parent tissue
Metaplasia
A reversible change during which one cell type is replaced by another
Occurs in response to a stressor; the new cell type may be more resistant to this stimulus
May be malignant if the stimulus is prolonged
Dysplasia
Disordered growth
Described as pre-cancerous changes that may or may not lead to cancer
Tissue architecture may appear disordered
Metastasis
Occurs when tumour cells implant in areas discontinuous with the primary tumour
Only seen in malignant tumours
Pathways of metastasis
- Direct seeding
- Lymphatic spread
- Haematogenous spread
- Implantation