The difference between a benign tumor and a malignant tumor explained

A woman screened to check for a malignant tumour (cancer)

 Depending on the types of cells forming a tumor, it can be benign or malignant.

This article examines benign and malignant tumors and notes the differences between them. While one can be deadly, the other is usually harmless.

Benign tumor

Benign tumors are not cancerous. They do not have the potential to spread or invade other tissues, and they also respond readily to treatments.

Benign tumors grow slowly and are harmless. However, they can be dangerous when they grow near a vital organ and press on it. For instance, a benign tumor pressing on a blood vessel can restrict blood flow. 

Also, benign tumors usually don't invade tissues. They often remain confined to their original location and don't spread to other body parts.

Different types of benign tumors exist, such as adenomas, fibroids, lipomas, keloids, and hemangiomas. 

Malignant tumor

Malignant tumors (also called cancer tumors) contain cancerous cells. Unlike benign tumors, malignant tumors are not easy to treat. Mutations in cells cause malignant tumors. As one grows older, old cells die off, and new cells are produced to replace the old ones.

DNA can get damaged in the process. This is also known as gene mutation. Gene mutations cause all types of cancer.

Mutations can result from mistakes from DNA copying made during cell division, viral infections, exposure to ionizing radiation, and exposure to chemicals (called mutagens).

Instead of dying off, the damaged DNA cells grow and develop, but they do so abnormally. The damaged cells multiply so fast that the immune system cannot curtail their growth. Soon, they form a tumor.

Cancerous cells hardly grow in one place. They typically break out from the tumor and spread to other parts of the body either by traveling through the bloodstream or the lymphatic system. 

The spread of cancer to other parts of the body is known as metastasis. It is the primary cause of death from cancer.

The most common types of malignant tumors are sarcomas, carcinomas, blastomas, and germ cell tumors

Major differences between benign and malignant tumors

Benign or Malignant? The table below lists the key differences between benign and malignant tumors.

Benign vs malignant tumor

Benign Tumor

Malignant Tumor

Contains cancerous cells



Spread to other parts of the body


Yes - Malignant tumors travel through blood and the lymphatic system to other parts of the body

Invades nearby tissues



Requires treatment

Yes - Benign tumors may not treatment as they are not dangerous

Always - Malignant tumors can lead to the death of a patient if not treated

Ease of Treatment

Easier to treat

Harder to treat - May require an operation

Shape of tumor

Usually have a smooth regular shape

May have a rough or uneven shape


Benign tumors may move around when you press them

Malignant tumors don't move around when you press them

Rate of growth

Benign tumors tend to grow slowly

Malignant tumors usually grow rapidly

Boundary Visibility

Tend to have clear boundaries

Spread to nearby tissues

How to prevent cancer

Many people don’t even know what causes cancer. How, then, will they know how to prevent it? 

Only about 36% of the people questioned by the World Cancer Research Fund identified alcohol as one of the causes of cancer, while about 44% thought stress is a risk factor for cancer.

Different things, including obesity, poor diet, alcohol, and genetics, can cause the formation of cancerous cells. Still, there are things you can do to reduce your risk of developing deadly malignant tumors. 

Things you can do to prevent the growth of cancerous tumors include:

  • Limit alcohol consumption
  • Limit the consumption of processed, refined, and canned foods
  • Avoid tobacco and secondhand smoke
  • Eat healthy meals comprising of fruits, vegetables, and other natural whole foods
  • Maintain a healthy weight
  • Reducing occupational exposure to ionizing radiation
  • Do not overexpose your skin to the sun
  • Exercise regularly
  • Avoid being exposed to dangerous chemicals that can cause changes to DNA
  • Go for regular checkups and screenings.

What to do when you notice a tumor growth

Photo by National Cancer Institute on Unsplash

According to the World Health Organisation, cancer accounted for over 10 million deaths in 2020. The most common cancers are breast cancer, lung, colon and rectum, prostate, skin, and stomach cancer.

It is best to act fast as soon as you notice abnormal growth in your body, as All types of tumors are easily treated when detected earlier.

Even though there are usually apparent differences between malignant and benign tumors, you might be unable to tell on your own.

It is always better to seek a professional for the correct diagnosis. If you notice an unexpected lump appear somewhere on your body, do not panic. Instead, please consult your doctor right away and have it checked out.

Run breast cancer self-examinations regularly to check for abnormal lumps sooner for common cancers like breast cancer.

Whether a tumor is benign or malignant, the earlier it is detected, the better its chances of being treated faster and effectively. 


  1. Campbell Denis. (2008). Millions are ignorant about the causes of cancer.
  2. Cancer Treatment Centers of America. (2017). What’s the difference? Benign and malignant tumours
  3. HBOC Society. (n.d.). How inherited gene mutations cause cancer.
  4. World Health Organisation. (2021). Cancer.