Female doctor talking to female patient
There are three types of tumors: benign, premalignant, and malignant.

Are All Tumors Cancerous?

When you hear the word “tumor” the first thought that probably comes into your mind is cancer, which can be frightening considering the high mortality rate associated with certain types of cancer. You may also be wondering, "Are all tumors cancerous or not?" What’s important to remember is that not all tumors are cancerous, so you shouldn’t jump to the worst-case scenario if you’re diagnosed with a tumor.

This article will outline what a tumor is, the different types of tumors, and briefly touch on treatment options so that you will have a better understanding of these terms, and can ask your physician the right questions if you’re ever diagnosed with a tumor in the future.

What Is a Tumor?


A tumor, also known as a neoplasm, refers to any abnormal growth or mass of tissue that can either be solid or fluid-filled. The term tumor is often used by physicians to refer to abnormal tissue masses before the exact size, source, type of growth, and the ability to spread has been determined.

When a tumor is larger, it is often referred to as a mass, while smaller lumps are typically termed nodules. It’s important to note that almost any type of tissue found in the human body can abnormally grow into a tumor.

Types of Tumors

Typically, tumors are categorized into three groups:

  • Benign
  • Premalignant
  • Malignant

Let’s take a look at each type in a little more detail.

Benign Tumors

Benign tumors are not cancerous and do not have the ability to spread. These types of tumors remain in their current form, and typically do not return once they are removed. Generally, benign tumors have a regular and smooth shape with a capsule covering them and are easily moved in the tissue.

These types of tumors are typically not harmful to your health. However, benign tumors may still interfere with surrounding nerves and blood vessels in the body, resulting in unwanted symptoms, including pain. Additionally, benign tumors located in endocrine tissue may disrupt the normal production of hormones, creating hormonal imbalances.

There are a variety of types of benign tumors including adenomas, osteochondromas, papillomas, fibromas, hemangiomas, nevi, and lipomas, among others.

You might be wondering what causes a benign tumor to develop? Well, the answer isn't always known; however, the development of benign tumors may be linked to a variety of factors, including:

  • Exposure to environmental toxins
  • Diet
  • Stress
  • Genetics
  • Trauma or infection

Premalignant Tumors

Premalignant tumors are also not cancerous, yet. However, on examination, they appear to be in the process of developing cancerous properties and therefore have the ability to turn into cancerous tumors.

Some premalignant tumor cells can pass on genetic changes that cause them to become more abnormal as they divide until they reach the point where they become cancerous. Premalignant tumors can take a long time to develop into cancer.

The changes that occur in premalignant tumors can range from mild to severe and there are various ways to describe these changes, based on their severity:

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  • Hyperplasia refers to abnormal cells that are dividing and increasing faster than normal. While these cells look normal on microscopic exam, there are more cells than normal.
  • Atypia refers to cells that are slightly abnormal.
  • Metaplasia refers to a change in the cell type that are normally found in the particular part of the body being examined.
  • Dysplasia refers to cells that are abnormal and fast growing.
  • Carcinoma in situ refers to cells that are very abnormal but have not grown into surrounding tissue. This type of change is often treated because of the heightened risk of turning into cancer.

Given the potential of premalignant tumors to become cancerous, they require close monitoring.

There are also a variety of premalignant tumors including actinic keratosis, cervical dysplasia, leukoplakia, and metaplasia of the lung, among others.

Malignant Tumors

Malignant tumors are cancerous and have the ability to grow large, and spread into surrounding tissues and organs by breaking away and traveling through the blood or lymphatic system – a process that is known as metastasis. The abnormal cells that comprise a malignant tumor multiply at a faster rate than normal cells.

When it comes to metastasis, it’s important to remember that the cancerous cells that have spread to other areas of the body are the same as the original ones – that being said, if lung cancer spreads to the brain, the cancerous cells growing in the brain are still lung cancer cells; however, they have developed the ability to invade other organs in the body.

Malignant tumors are the most worrisome type of tumor because they can be fatal, and are often difficult to treat.

There are approximately 200 types of malignant tumors, including carcinoma, sarcoma, giant cell tumor, and blastomas, among others.

Some key points to take away from this section, include:

  • Tumors are NOT always cancerous.
  • Benign tumors do NOT have the ability to spread.
  • Premalignant tumors are NOT cancerous but have the potential to become cancerous.
  • Malignant tumors are cancerous and have the ability to spread into other tissues and organs.

Tumor Treatment

As previously mentioned, when it comes to benign tumors, after their removal, most of them do not recur. In some cases, a watchful waiting approach may be used to determine if the tumor is causing an issue. In some cases, surgery may be recommended to remove the benign tumor, without damaging surrounding tissues, while in other cases, patients may be offered medications and/or radiation to treat their benign tumor.

In the case of premalignant tumors, the patient should be monitored closely, and if the tumor looks to be turning into cancer, the necessary treatment should be initiated.


When it comes to malignant tumors, they are usually treated with more extensive and invasive treatment plans. There are various treatment options for malignant tumors including surgery, chemotherapy, and radiation.

So, Are All Tumors Cancerous or Not?

While the word “tumor” may be scary, it’s important to remember that not all tumors are cancerous. Ensure that you get any lumps that you find on self-exam checked out by your physician.

In many cases, nodules and lumps will prove to be benign tumors that are harmless; however, if you are diagnosed with a malignant tumor, the earlier you seek treatment, the better your prognosis will be.