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Tumors can either be cancerous (malignant) or noncancerous (benign).

Benign vs. Malignant Tumors

A tumor is a solid or fluid-filled mass of tissue which can appear almost anywhere in the body. Tumors can be any shape or size, and may be benign or malignant.

The Definition of Benign and Malignant

People often talk about benign and malignant tumors, but what does this mean? The dictionary definition of benign is “not recurrent; favorable for recovery with appropriate treatment.”


When talking about tumors, benign means not cancerous or directly threatening to life. It is the opposite of malignant, which is defined as "tending to become progressively worse and to result in death; having the properties of anaplasia, invasiveness, and metastasis; said of tumors."

This means that cells in malignant tumors can change their structure and travel to other areas of the body. These are the type of tumors which cause cancer, and if left untreated, they may be fatal.

Benign vs. Malignant Tumor Characteristics

Benign Tumors

Benign tumors can affect many different parts of the body including organs, glands, nerves, connective tissue and the skin. They will vary in size and shape depending on where they are and what is causing them.

Benign tumors are often surrounded by a sac which is created by the immune system to keep them separated from the rest of the body. Benign tumors grow slowly, if at all, and cannot spread to other areas.

These tumors are not harmful in themselves but may cause issues such as pain or discomfort if they press against a blood vessel or nerve. Sometimes a benign tumor forms in the endocrine system, on glands such as the pituitary gland or the thyroid. This can cause hormonal imbalances and further, potentially serious symptoms. These symptoms will depend on exactly which glands and hormones are affected.

Malignant Tumors

The immune system is usually very effective at destroying cells which could become cancerous, but sometimes a few slip through the net. These cells can quickly grow into malignant tumors, putting your health at risk.

Malignant tumors are cancerous and can spread to different areas of the body through the blood or lymphatic system. They grow and travel quickly, meaning that early detection is vital if they are to be stopped. These tumors are graded on a scale from 0–4 which is used to indicate their size and how much they have spread.

Like benign tumors, malignant tumors can affect many different areas of the body. Some of the most common are the breasts, testicles, prostate gland, lungs, liver, and stomach.

What Is the Difference Between Benign and Malignant Tumors?

The main difference between these two types of tumor is that benign tumors are usually harmless, whereas malignant tumors cause cancer.

Benign tumors also stay in one area, but malignant tumors can spread throughout the body, affecting different organs and tissues.

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The treatment for benign and malignant tumors is also different. Benign tumors often require no treatment. However, if they are causing symptoms, they may be removed or reduced in size.

Malignant tumors must be removed, even if they are not currently causing any symptoms. Early removal of malignant tumors is vital to reduce the risk of cancer cells spreading throughout the body.

Are There any Similarities Between Benign and Malignant Tumors?

There are many similarities between benign and malignant tumors. They can both affect almost any part of the body, and both can cause masses which may be seen or felt through the skin.

Both benign and malignant tumors may cause various symptoms depending on where they are located within the body. Equally, both may be symptom-free in the early stages of development.

There is no hard and fast rule for distinguishing between benign and malignant tumors without a biopsy. This is a medical test where your physician will take a small sample of tissue from your tumor and check it for cancer cells. If these are found, the tumor is malignant and will need to be removed.

In addition to benign and malignant tumors, there is a third type of tumor known as premalignant tumors. This type of tumor is not currently malignant but has the potential to become so in the future. Therefore these type of tumors need close monitoring to prevent them from becoming a health risk.


What to Do If a Tumor Is Found

If you find a new lump, bump or tumor anywhere on your body, it is important not to panic. However, you should get it checked by your physician as soon as possible.

In the vast majority of cases, it will turn out to be something harmless, but in the unlikely event that your tumor is malignant, you will want to get it treated as early as you can. This will reduce the risk of the tumor spreading and increase your chances of making a full recovery.