A malignant tumour is a cancerous tumour, and it contains cells that have the ability to spread and invade surrounding tissues and organs. This type of tumour can cause damage that is potentially fatal.
A malignant or cancerous tumour contains cancer cells. These cells originate from one beginning to change, divide and rapidly grow out of control. A tumour is formed when enough cancer cells grow to form a mass.
A tumour can form but not contain cancerous cells. This is known as a benign tumour and is considered relatively harmless. This type of tumour stops growing due to not having any more room to do so.