Difference between benign and malignant tumours

Benign tumours are usually limited in their pattern of growth, so remain localised and do not spread. Under a microscope, benign cells resemble their tissue of origin, and often are enclosed in a fibrous capsule which limits the tumour's size. Benign tumours generally do not cause problems unless located in a confined space.

Malignant cells often have irregular structures, including large nucleus, little cytoplasm, and little specialised structures. They do not resemble the tissue of origin, and are usually non-encapsulated with poorly defined borders, and can invade surrounding tissue. Malignant cells may also metastasise, spreading to local or distant parts of the body via the lymphatic or blood vessels. Another difference is anaplasia (loss of differentiation) in malignant cells.





- Rachel Yee