What is a benign tumor?

A tumor is a lump of damaged cells. In a benign tumor, the cells keep to themselves and don't bother the other cells around them.

By definition, a "tumor" is an abnormal collection or growth of cells. Tumors can be either benign or malignant.

Malignant tumors (cancers) are able to invade into surrounding tissues and organs, and to spread, or metastasize, to other organs in the body.

On the other hand, a benign tumor is a tumor that (unlike cancerous tumors) does not have the ability to invade into surrounding normal tissues and organs, and does not have the ability to spread (metastasize) to other organs in the body.

Dr. Ajay K. Sahajpal, MD
Transplant Surgeon

A tumor is essentially uncontrolled cell growth. We classify it as benign or malignant. Benign tumors generally do not spread beyond their confines or metastasize. They are not considered cancers. Malignant tumors are essentially cancers.

Dr Camille

A tumor is an abnormal growth of cells.

Normal cells will grow and divide when the body needs them; these cells will be destroyed if they are damaged or if the body no longer needs them (a process called apoptosis). A delicate balance is maintained between newly dividing cells and destruction of old cells. A tumor develops when this process goes wrong—if damaged or old cells are not destroyed when they should be, or if new cells are formed when not needed.

A benign tumor is not cancerous and will not spread to other areas. It is an abnormal growth of otherwise "normal" cells. However, the location of a benign tumor can be dangerous if in a confined area (pushing against sensitive structures) and may lead to symptoms; example—a benign brain tumor.

Your doctor will conduct tests (biopsy, MRI, etc.) to determine if a tumor is benign.

Dr. Daniel A. Nader, DO
Pulmonary Disease Specialist

A benign tumor is a mass or lump in an organ that does not have malignant or metastatic potential. This would be like a benign fatty tumor that typically is found in limbs or on the body. These are usually composed of fat tissue, and they have no possibility of becoming malignant or metastasizing to other parts of the body.

A benign tumor is a growth that is not cancer. It does not invade nearby tissue or spread to other parts of the body.

This answer is based on source information from The National Cancer Institute.


Dr. Steven G. Eisenberg, DO
Hematologist & Oncologist

A benign tumor is a good thing in the world of oncology. This represents an abnormal growth in the body that does not have the ability to spread through the body (metastasize). There are numerous growths that can occur in the human body that can be characterized as benign tumors. A benign growth of fat cells is called a lipoma, for example. One type of benign growth in the breast is a fibroadenoma. Just a reminder though, any abnormal suspicious mass in the breast must be biopsied, even with a normal mammogram. Hopefully, it will be benign.

Benign refers to tumors that do not spread to other organs or sites.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.