Benign tumors are noncancerous growths in the body. They can occur anywhere in the body, grow slowly, and have clear borders. Unlike cancerous tumors, they don’t spread to other parts of the body.

If you discover a lump or mass in your body that can be felt from the outside, you might immediately assume it is a cancerous tumor. For instance, women who find lumps in their breasts during self-examinations are often alarmed. However, most breast growths are benign. In fact, many growths throughout the body are benign.

Benign growths are extremely common, and more than 90 percent of breast tissue changes are benign. Benign bone tumors, similarly, have a higher prevalence than malignant bone tumors.

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Benign and malignant tumors have distinct characteristics. Some of these properties make diagnosing the tumor easier for doctors.

Benign tumors:

  • typically grow slowly
  • have smooth, distinct borders
  • do not grow into surrounding tissue or organs
  • do not invade other parts of the body

Malignant, or cancerous, tumors:

  • can grow quickly
  • have irregular borders
  • can grow into surrounding tissue or organs
  • can spread to other parts of the body

The exact cause of a benign tumor is often unknown. It develops when cells in the body divide and grow at an excessive rate. Typically, the body is able to balance cell growth and division. When old or damaged cells die, they are automatically replaced with new, healthy cells. In the case of tumors, dead cells remain and form a growth known as a tumor.

Cancer cells grow in the same manner. However, unlike the cells in benign tumors, cancerous cells can invade nearby tissue and spread to other parts of the body.

While it’s unclear why benign tumors develop, potential causes have been identified. These include:

  • environmental factors, such as toxins, radiation, or chemicals
  • inflammation or infection
  • diet
  • local trauma or injury
  • stress
  • genetics

Anyone can develop a benign tumor, including children, though adults are more likely to develop them with increasing age.

There are a fair number of benign tumors that can develop in different parts of the body.

Benign tumors are classified by where they grow. Lipomas, for example, grow from fat cells, while myomas grow from muscle. Different types of benign tumors are included below:

Adenomas

Adenomas form in the epithelial tissue, a thin layer of tissue that covers glands, organs, and other internal structures. Examples include polyps that form in the colon or growths on the liver. Adenomas can also grow on the adrenal, pituitary, or thyroid glands.

These tumors can become malignant. In fact, in the colon, one in 10 adenomas become cancerous.

Lipomas

Lipomas grow from fat cells and are the most common type of benign tumor. One in 1,000 people will develop a lipoma in their lifetime. They are often found on the back, shoulders, arms, or neck. They are usually soft and round, and can be moved slightly under the skin.

Lipomas may not require treatment unless they are painful or growing quickly. They also rarely become cancerous, according to the American Academy of Orthopaedic Surgeons. Although they can occur at any age, lipomas are more common in people ages 40 to 60.

Myomas

Myomas grow from muscle or in the walls of blood vessels. They can also grow in smooth muscle, like the kind found inside organs such as the uterus, stomach, or gastrointestinal tract. If the myoma develops in the uterus, it’s also called a uterine fibroid.

Fibroids

Fibroids, or fibromas, can grow in the fibrous tissue or connective tissue found in any organ, tendon, or ligament. They are most common in the uterus, where they are known as uterine fibroids. (Uterine fibroids are also known as uterine myomas or leiomyomas.)

Fibroids in the uterus can cause symptoms such as heavy vaginal bleeding, pelvic or back pain, and abdominal pressure. They are rarely cancerous, but fibroid surgery may be necessary to cure the symptoms.

Nevi

Nevi are also known as moles. These are common, noncancerous growths on the skin ranging in color from tan or brown to pink and black.

Certain types of nevi, such as dyplastic nevi, are more likely to develop into skin cancer. Regular skin checks are necessary to catch these changes.

Other types of skin growths, such as skin tags, are considered benign skin neoplasms. Like moles, these unusual growths should be watched for signs of developing cancer.

Hemangiomas

Hemangiomas are benign tumors that grow from blood vessels. This buildup of blood vessel cells can occur in the skin or internal organs, such as the liver or colon. When it happens, you may see a red or bluish mark on the skin. These often appear on the head, neck, or trunk. Some people consider these a birthmark, and they frequently go away on their own.

Hemangiomas can interfere with vision or hearing if they are near the eyes or ears. They can also bleed or develop ulcers. Some require treatment with medicine or laser therapy. Surgery may be necessary in some cases.

Meningiomas

Meningiomas are benign tumors that develop in the meninges, or the membrane that surrounds the brain and spinal cord. These tumors may cause no symptoms, but if they grow to be large, or if they press on the brain or spinal column, they can cause symptoms. These symptoms include headache, seizure, weakness on one side, and vision problems.

Rarely, these tumors can turn cancerous. Research shows 1 to 3 percent of meningiomas transform into malignant brain tumors.

Neuromas

Neuromas are benign brain tumors that grow within nerves. They can occur almost anywhere in the body. Schwannomas develop on the nerve sheaths in the peripheral nervous system. Neurofibromas develop on the nerve tissue, and they can grow in the skin, under it, or even deeper in the body, such as in the bladder.

Osteomas

Osteomas, also known as exostosis, are abnormal but benign growths of new bone over existing bone. This can occur on any bone of the body. When the bone growth is covered with cartilage, it’s called an osteochondroma.

Some growths can be painless and don’t need treatment. Others, however, can be painful and may need to be removed with surgery. They do not have a chance of becoming malignant.

Not all tumors, cancerous or benign, have symptoms. Depending on the tumor’s location, numerous symptoms could affect the function of important organs or the senses.

Depending on the location, possible symptoms of a benign tumor include:

Benign tumors may be large enough to detect, particularly if they’re close to the skin. However, most aren’t large enough to cause discomfort or pain. They can be removed if they are. Lipomas, for example, may be large enough to detect, but are generally soft, movable, and painless.

Some skin discoloration may be evident in the case of benign tumors that appear on the skin, such as nevi or hemangiomas. Anything that looks abnormal should be evaluated by a doctor.

Other benign tumors may cause specific symptoms based on where they’re growing. These include:

Benign brain tumor

If you have a benign brain tumor, you may experience:

These symptoms develop because a meningioma or other tumor is pressing on the brain or spinal column. Symptoms can impact your day-to-day life and may require treatment.

Benign breast tumor

Most breast tissue changes are benign, but the tumors may still be large enough to detect by hand. Symptoms of these noncancerous growths in the breast include:

  • raised bump on or under the skin
  • large enough to feel, if close to the skin
  • firm or soft when you press
  • may move when you press

Benign bone tumor

Bone tumors like osteomas or osteochondromas are usually painless, but they can cause symptoms if they are large or near joints. These symptoms include:

  • pain, especially in joints or muscles
  • pressure on bones or nerves
  • difficulty with full range of motion
  • one limb is shorter than the other

Doctors use a variety of techniques to diagnose benign tumors. The key in diagnosis is determining if a tumor is benign or malignant. Only lab tests can determine this with certainty.

Your doctor may begin by performing a physical exam and collecting your medical history. They’ll also ask you about your symptoms.

If you don’t already have a primary care doctor, you can browse doctors in your area through the Healthline FindCare tool.

Many internal benign tumors are found and located by imaging tests, including:

Benign tumors often have a visual border of a protective sac that helps doctors diagnose them as benign. Your doctor may also order blood tests to check for the presence of cancer markers.

In other cases, doctors will take a biopsy of the tumor to determine whether it’s benign or malignant. The biopsy will be more or less invasive depending on the tumor’s location. Skin tumors are easy to remove and only require a local anesthetic, while colon polyps would require a colonoscopy, for example, and a stomach tumor may require an endoscopy.

Not all benign tumors need treatment.

In many cases, benign tumors will be monitored carefully. Noncancerous moles or colon polyps, for example, can turn into cancer at a later time. But they may never require intervention.

Some types of internal benign tumors may cause other problems. Uterine fibroids can cause pelvic pain and abnormal bleeding, and some internal tumors may restrict a blood vessel or cause pain by pressing on a nerve.

If your doctor decides to pursue treatment, the specific treatment will depend on the location of the tumor. It may be removed for cosmetic reasons if, for example, it’s located on the face or neck. Other tumors that affect organs, nerves, or blood vessels are commonly removed with surgery to prevent further problems.

  • Watch-and-wait: If your tumor is small and isn’t causing any symptoms, your doctor may recommend taking a watch-and-wait approach. In these cases, treatment could be riskier than letting the tumor be. Some tumors will never need treatment.
  • Medication: Medicated gels or creams may help reduce some tumors, such as hemangiomas. Steroids might also shrink or reduce some tumors that are causing symptoms like pain or pressure.
  • Surgery: Tumor surgery is often done using endoscopic techniques, meaning the instruments are contained in tube-like devices. This technique requires smaller surgical incisions, if any at all, and less healing time. Procedures like upper endoscopies and colonoscopies require almost no recovery time. Skin tumor biopsies take a few weeks to fully heal and require basic recovery procedures like changing the bandage and keeping it covered.
  • Radiation: If surgery can’t safely access the tumor, your doctor may prescribe radiation therapy to help reduce its size or prevent it from growing larger.

The more invasive the treatment, the more recovery time will be needed. Recovery from a benign brain tumor removal, for example, can take longer. Even once it’s removed, you may need speech therapy, occupational therapy, or physiotherapy to address problems the tumor left behind.

While maintaining a healthy lifestyle, exercising, and eating a balanced diet can prevent health problems including some types of cancers, there aren’t natural or alternative remedies for benign tumors on their own.

Many benign tumors can be left alone if they show no symptoms and create no complications. You’ll be told to simply keep an eye on it and watch for changes.

If you don’t have your tumor removed, your doctor may have you come in for routine exams or imaging scans to ensure that the tumor isn’t growing larger.

As long as the tumor isn’t causing you pain or discomfort, and it isn’t changing or growing, you can live with a benign tumor indefinitely.

While many growths and tumors will turn out to be benign, it’s still a good idea to make an appointment with your doctor as soon as you detect a growth or new symptoms that could indicate a tumor. This includes skin lesions or unusual-looking moles.

It’s also important to see your doctor if you notice any changes in a tumor that was previously diagnosed as benign, including growth or a change in symptoms. Some types of benign tumors can become cancerous over time, and early detection can make all the difference.