Tumors can be benign or malignant.
* Benign tumors are non-cancerous and do not spread to other parts of the body. They can often be removed surgically.
* Malignant tumors, also known as cancers, are cancerous and can invade surrounding tissues and spread to other parts of the body (metastasis).
The uncontrolled cell growth and division in tumors is often caused by mutations in genes that regulate cell cycle and growth.
