Benign and malignant tumours
A tumour is an abnormal mass of cells that replicate in an uncontrolled manner.
Tumours are classified depending on their ability to invade other tissue.
- Benign tumours are masses of abnormal cells that do not damage surrounding cells as they are unable to invade other tissue types.
These tumours are usually harmless and are easily removed through surgery. As benign tumours are unable to spread to other parts of the body they are not classified as cancerous.
- Malignant tumours can damage surrounding cells and invade other tissue types, spreading to other parts of the body. These tumours are cancerous.
Metastasis is the spread of malignant tumour cells to other parts of the body. As cancerous cells spread, the cancer becomes harder to treat.