What is the difference between cancerous tumors and benign ones?

[bobbobwhite]

If cancer cells are normal cells with uncontrolled growth, what is the difference between cancerous tumors and benign ones? Aren't both due to uncontrolled cell growth? What makes the cancerous ones deadly and not the benign ones?

Thanks in advance for the correct answer to this pretty basic medical question from someone who knows the specific details. No guesses, please.

 

[hypatia]

Malignant tumors can grow very quickly and destroy nearby tissue and spread to other areas of the body.
Benign tumors can grow large but do not spread to other parts of the body.

 

[bobbobwhite]

94 pound benign tumor

It's not just tissue growth. I read where a woman had a 94 pound benign tumor removed from her abdomen and it didn't kill her, but much smaller cancerous tumors can kill. So, it's not just tumor size obviously as, logically, there has to be other destruction working with uncontrolled tissue growth, such as damaged organ and/or biochemical function , etc.

Still do not have the very specific answer I am seeking.

 

[hypatia]

The tumors in the abdomen have room to grow, and do not invade vital organs, or other areas of the body. You may have a very large tumor, but the area that its attached to, is non-vital. The word benign means its relatively well-behaved and easy to treat. There are people who die of benign tumors. Examples of deadly benign tumors may include tumors in the brain and spinal areas.
A smaller cancerous tumor invades other vital organs, and often sends a shock wave of cancer cells to the blood or lymph systems. When this happens it is called, Metastasized. Its harder to control them.
Treatments often leave immune systems weak, and open to secondary infections.