Is it cancer? How to differentiate between benign and malignant tumours

Emeh Joy

When people notice a new lump on their body, especially on the breast, the first thought is usually cancer. Not all tumours are malignant (cancerous), but how do you differentiate between a malignant and benign tumour?

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

The word “tumour” sounds scary, but it shouldn’t be so. A tumour is a cluster of abnormal cells. Abnormal growth of cells can form a tumour (appears like a lump). In some cases, it is not a cause for serious concern. 

Depending on the types of cells that are forming a tumour, the tumour can be:

  • Benign
  • Malignant

It will help to have an idea of what each tumour looks like and how to differentiate them. 

This article will take a closer look at the benign and malignant tumours and note the difference between the two. One of the tumours can be deadly, while the other is usually harmless. 

Benign tumours

Benign tumours are tumours that are not cancerous. They do not have the potential to spread or invade other tissues. They also respond readily to treatments. 

Benign tumours grow slowly and are harmless. However, they can be dangerous when they are growing near a vital organ, such that they press on the organ. For instance, a benign tumour pressing on a blood vessel can restrict blood flow. 

“Benign tumours don’t generally invade. They usually push the normal tissue to the side”, said Fernando Garcia, medical doctor and pathologist at the Cancer Center hospital in Philadelphia.

Types of benign tumours include adenomas, fibroids, lipomas, keloids and hemangiomas

Malignant tumours

Photo by SHVETS production on Pexels

Malignant tumours contain cancerous cells. Unlike benign tumours, malignant tumours are not easy to treat.

As we grow 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.3 

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 tumour.

Cancerous cells hardly grow in one place. They typically break out from the tumour and spread to other parts of the body either by travelling 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 tumours are sarcomas, carcinomas, blastomas and germ cell tumours

Major differences between benign and malignant tumours

Below are key things that differentiate benign tumours from malignant tumours.

Benign tumour versus malignant tumour



Don't contain cancerous cells

Contain cancerous cells

Don't spread to other parts of the body

Travel through blood and the lymphatic system to other parts of the body

Don't invade nearby tissues

Can invade nearby tissues

May or may not require treatment

Always require treatment to save life

Easier to treat

Harder to treat

Usually have a smooth regular shape

May have a rough or uneven shape

May move around when you push them

Don't move around when you push them

Tend to grow slowly

Usually grow rapidly

Tend to have clear boundaries

Spread to nearby tissues

Malignant tumours can be prevented

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.1

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 tumours. 

Things you can do to prevent the growth of cancerous tumours 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 ionising 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 an abnormal 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 were breast cancer, lung, colon and rectum, prostate, skin and stomach cancer.4

All types of cancer are better treated when detected earlier. Thus, it is best to act immediately you notice an abnormal growth.

Even though there are usually clear differences between malignant and benign tumours, 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, consult your doctor right away and have it checked out.

For common cancers like breast cancer, running breast cancer self-examinations regularly might help a person to notice abnormal lumps sooner.

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


  1. Campbell Denis. (2008, October 5). Millions are ignorant about the causes of cancer. The Guardian. 
  2. Cancer Treatment Centers of America. (2017, December 25). What’s the difference? Benign and malignant tumours.
  3. HBOC Society. (n.d.). How inherited gene mutations cause cancer. 
  4. World Health Organisation. (2021 September, 21). Cancer. 

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