Types of Benign Tumor

Doctor and oncologist examining a patient with a benign tumor

People often get scared when they notice abnormal growths in their bodies. Not all tumors are cancerous; some are just harmless benign tumors. Different types of benign tumors exist, including adenomas, lipomas, and neuromas.

A tumor is an abnormal tissue mass that grows, forming new cells when they shouldn't—they are also formed when old ones don't die off when they should. Tumors usually start as small outgrowths and expand to bigger sizes. They can be either malignant or benign. Benign means they are non-cancerous, while malignant means they are cancerous.

However, most tumors people have are benign. In fact, benign tumors are as common as infections. They could range from a non-infectious mass to a large abdominal mass. 1 in 5 people has it, Charles Okwonna (MBBS), FMCR, Consultant, Clinical and Radiation Oncologist at Prince Faisal Cancer Center, KSA told SemicHealth.

This article discusses benign tumors and their types. It will also discuss the causes and symptoms of benign tumors, how to differentiate between benign and malignant tumors, and when to see a doctor for a tumor diagnosis.

Meaning of Benign Tumor

A benign tumor is a type of tumor that is not cancerous and rarely causes any life-threatening effects. They are also incapable of invading other neighboring tissues, unlike malignant tumors.

Benign tumors don't spread to adjacent tissues because the borders of the tumors usually have coverings called capsules. This capsule prevents it from spreading to other tissues. This is one important characteristic that differentiates benign tumors from malignant tumors.

Benign tumors are the most common type of tumor found in different body parts and tissues, such as dental tissue tumors, vascular or neural tumors, osseous tumors in the bone, uterine tumors, and breast tumors.

Benign tumors always appear as uncoordinated tissue growth capable of growing into different forms. They are commonly detected and can be removed if the person with this tumor reports to the appropriate health care providers.

Benign tumors often grow slowly and may not cause pain. However, you will notice them when they develop because they enlarge the affected area, and the mass may compress the tissues around it.

Most benign tumors only cause symptoms when they grow in an enclosed space, such as the skull, sinus, inside bones, or even respiratory tracts. In such places, they can obstruct blood flow or grow into nerves, causing neurological issues if not treated.

If you notice abnormal growth on any part of your body, it is best to report it to your doctor for proper diagnosis and treatment. Some types of benign tumors will resolve with topical medications, pills, or injections, while some will need more advanced treatment like surgeries to remove them.

Types of Benign Tumors

Benign tumors are classified into various types based on their different locations in the body. The common types of benign tumors include:

1. Lipomas

These are the most commonly found benign tumors in the body Lipomas are benign tumors that develop from fat cells; usually soft and round, they can be felt or moved slightly. They can be easily seen in the arms, shoulders, necks, and back, but they can also be seen in other areas of the body.

Lipomas can develop at any age. This means they can develop in children as well as in adults. They usually don't require treatments, but exceptions can be when the tissues are growing fast and becoming painful.

2. Adenomas

Adenomas are classified under benign tumors because they are non-cancerous tumors. They are often found in the epithelial tissue. Epithelial tissues are the tissues that form the covering of your organs and glands.

They have a slow growth like other benign tumors. Adenomas are always found growing around the hormone-producing glands (glandular organs), and they are usually named based on their location.

Some typical adenomas include parathyroid adenoma, colon polyps, pituitary adenoma, and adrenal adenoma. However, Adenomas should be treated when they occur because they can sometimes become malignant.

3. Myomas

Myomas, commonly known as uterine fibroids, are smooth, non-cancerous tumors that form around the uterus.

This type of benign tumor varies from one individual to another and causes symptoms like a heavy flow of menstrual blood and abdominal pain - and sometimes can be asymptomatic.

Myomas can be located precisely inside the uterus or sometimes on the outer surface of the uterus.

4. Nevi

A nevus is a non-cancerous growth on the skin with varying colors. It usually develops when there is a cluster of melanocytes. (Melanocytes are cells that produce melanin).

This growth can appear as brown, black, or pink tumors. Some types of nevi, like dysplastic nevi, tend to develop into skin cancer, so it is best not to overlook them.

5. Neuromas

Neuromas are types of benign tumors that often develop when some injured nerves begin to heal uncontrollably. This often leads to lumps and non-neuronal tissue growth.

While some neuromas can form in specific locations (especially the third and fourth toes) others can appear in different areas.

Neuromas can be treated in different ways but commonly through surgery, depending on the progression and location.

6. Osteoma

Osteomas are non-cancerous tissues that grow when a new bone grows over another bone. This can occur in two forms:

  • When the bone tumor grows over another bone (also called homoplastic osteoma)
  • The bone tumor grows on another tissue (and forms a heteroplastic osteoma).

Osteomas require treatment when they begin to have symptoms. The treatments can involve different forms of surgery.

7. Hemangioma

Hemangioma is an extra blood vessel that appears in the skin at birth. It can develop anywhere in the body, but it is most commonly seen on the scalp, chest, face, or back.

The traces of hemangiomas usually disappear when the affected child reaches about 10 years of age. So, when it appears in a newborn, it rarely needs treatment.

Treatment can only be required when it causes other effects, like impaired vision, and breathing, or impairs other essential body functions.

Effects of Benign Tumors

Although benign tumors are not cancerous, some of them can cause adverse health effects.

  • Benign tumors can displace the structures of neighboring tissues and might also cause nerve damage. This happens when the tumor grows continuously.
  • They can also cause loss of function and resorption of adjacent tissues.
  • In the case of tumor progression, benign tumors might develop into malignant tumors, thereby becoming cancerous.

Causes of Benign Tumors

Hormonal changes are one of the most common causes of benign tumors

The actual cause of most benign tumors is unknown (i.e., idiopathic). But for those that are not idiopathic, Dr. Okwonna says, their causes vary depending on their location.

However, benign tumors develop just like other tumors. The standard process of the body is that when cells die, they get replaced by new cells. In the case of benign tumors, new cells continue to grow even when not needed by the body, and dead cells persist.

Some benign tumors like keloids develop following an injury or a scar on the skin. In a bid to heal, cells in that area can overgrow, causing a scar that is even larger than the original wound.

Chains of reactions and changes going on within the human body can also cause benign tumors.

The majority of the lumps are linked to hormonal changes. For instance, they can form at a point in the menstrual cycle when estrogen causes the breast tissue to proliferate in preparation for pregnancy. Inflammatory factors can also cause benign tumors, Dr. Okwonna says.

Some benign tumors are also carried by genetic materials people inherit from birth. For instance, benign tumors like keloid have the tendency of running in families. A 2017 study linked the occurrence of keloids in Africans and Asians to genetic elements at 15q21.2‐22.3.

Other possible causes of benign tumors include

  • Certain infections
  • Toxins
  • Chemicals or radiation
  • Stress

Common Symptoms of Benign Tumors

Some abnormal tissue growths are accompanied by fever and headache.

Most benign tumors are asymptomatic and can only be detected when they form visible swellings. However, some may cause symptoms that can disrupt everyday life, especially the ones that grow into organs, nerves, and blood vessels.

Some common symptoms of benign growths include:

  • Loss of appetite
  • Presence of night sweats
  • Cases of weight loss
  • Fever
  • Chills
  • Occasional pain

When to see a doctor for tumor diagnosis

While benign tumors do not frequently cause harm to the body, there are exceptional cases when you may need to show more concern.

Dr. Okwonna shared more insight on this. He said, while some benign tumors such as breast lumps, keloids, and fibroids usually don't transform into cancerous, others such as moles that grow on the skin can transform into malignancy, especially when exposed to the sun.

You should see your doctor if the size of your tumor changes, if the borders go from smooth to rough, if it starts itching or causing pain and if the color changes (e.g., from a darker shade to red), Dr. Okwonna further added.

The only sure way to ascertain if your tumor is benign or malignant is to see your doctor, who will examine you physically and run tests like a biopsy. If cancer is detected (which is often not the case), they will refer you to an oncologist who will give you the proper treatment.


Most abnormal growths in the body are benign tumors. There are different types of benign tumors, as mentioned in this article, and they are rarely life-threatening. However, it is always advisable that you visit your healthcare providers when you start noticing any abnormal growth.

Healthcare providers often advise adults to go for regular screening. During such screenings, your doctor will run tests to be sure the lump on your body is not harmful.

Your healthcare providers are also in the best position to diagnose and let you know if you should go in for treatment or not.


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  6. Shanavas M, Chatra L, Shenai P (2013) Multiple Peripheral Osteomas of Forehead: Report of a Rare Case
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  8. Zablago M, Dreyer MA (2022) Neuroma