Types of Benign Tumors
This article explains the symptoms, types, causes, risk factors, and treatment options associated with benign tumors.
A benign tumor is a noncancerous and usually harmless mass of cells that can grow anywhere in your body.
Our bodies create a tumor when a process called cell growth and division goes wrong. Our bodies are always creating cells to replace or repair other cells within our organs, blood, and elsewhere. It is how our bodies heal cuts, create scar tissue, heal bone fractures, grow hair, and make more blood. During cell growth and division, cells die, and other cells divide to create new cells.
Although it is not clear why tumors sometimes form during this process, benign tumors are made up of cells that either do not die as they should or divide too quickly.
The body can also produce cancerous tumors. Another name for these is malignant tumors. Generally, benign tumors are much more common than malignant ones. For brain tumors alone, experts estimate diagnoses of 63,040 new benign brain and central nervous system tumors in 2022. This is 2.43 times as many malignant brain tumors.
Benign tumors are not typically harmful, but they sometimes grow in a difficult spot or grow too large and threaten essential organs or parts of the brain. When that happens, benign tumors can cause unwelcome symptoms and require surgery.
Benign tumors, unlike cancerous tumors, do not have the ability to spread outside of the area where they are growing. They usually grow more slowly than cancerous tumors, but some cancerous tumors grow slowly as well.
If the benign tumor is in an area where you can feel it, you may find that you can move it around a little bit. It usually feels smooth and has a distinct border. A cancerous tumor, on the other hand, is not usually as mobile or uniform-feeling.
Benign tumors are less likely than cancerous tumors to need treatment. They are also less likely to be life threatening, and they usually do not grow back if they are surgically removed.
For most benign tumors, there is no known medical cause, and they happen by chance.
Throughout life, the DNA inside a cell changes. Some of these genetic changes (mutations) can cause a cell to grow and divide or not die appropriately. Risk factors for these genetic changes can be some of the same ones as for malignant tumors. These include:
- previous radiation exposure
- inherited genetic conditions
- exposure to chemicals capable of causing mutations
In rare cases, people inherit a mutation — meaning that their cells develop it when they are in the uterus — that can contribute to the development of specific types of benign tumors.
- For instance, a genetic mutation of the PTEN gene can cause benign tumors called hamartomas to form in different parts of your body. This PTEN genetic mutation can also cause cancerous tumors to develop.
- A rare genetic condition called neurofibromatosis type 1 (NF1) also causes benign tumors (neurofibromas) on or under the skin and sometimes along nerves in the body.
- Tuberous sclerosis complex is another rare genetic disorder that causes benign tumors to grow in the body. These tumors sometimes affect the brain.
Can a benign tumor become malignant?
People with benign tumors sometimes worry that they will become cancerous, but usually, this does not happen.
Occasionally, however, benign tumors contain precancerous cells, which have the possibility of turning into cancer. For instance, a screening colonoscopy might find benign polyps that have the potential to turn into cancer over time. For this reason, a healthcare professional will remove them during the colonoscopy.
Some tumors, such as breast phyllodes tumors, can have cells that — when examined under a microscope — classify the tumor as benign, borderline, or cancerous. These tumors are treated differently depending on the cells they contain.
There are many types of benign tumors, including (but not limited to) the following.
Adenomas are benign tumors that grow in tissue that covers organs and glands. They can occur in the colon (as polyps), breast (as fibroadenomas), uterus, pituitary gland, thyroid, bile duct, and other tissues and organs.
In the colon, adenomas can cause blood in the stool. Pituitary adenomas in the brain can cause vision problems and headaches.
Brain and neurological tumors
Many possible neurological symptoms can result from benign tumors in the brain and spinal cord.
Chondromas are made from cartilage tissue and can grow in the sinuses, skull bones, and bones of the hands, feet, arms, ribs, and thighs.
Symptoms of chondromas depend on where they are growing but can include:
- vision changes
- a lump
These are benign tumors that grow at the ends of long bones, such as the femur in the leg.
Symptoms of chondroblastomas include:
- joint stiffness
- muscle shrinkage near the tumor
Fibroids, or myomas, grow in the smooth muscle wall of the uterus.
Symptoms of fibroids include:
- heavy bleeding or painful periods
- lower back pain
- painful sex
- bloating of the lower belly
- potential difficulty becoming pregnant
Most hamartomas are benign, but some are malignant. They can occur all over the body, including in the breasts, lungs, and heart.
They do not often cause symptoms unless they are in an area where you can feel a lump or mass.
A hemangioma is made up of blood vessels.
Symptoms vary depending on where they develop. They usually occur on the skin’s surface — most often on the face and neck — and appear red or blue and soft. In some areas, they can also cause muscle pain and swelling.
Lipomas are tumors made of fat cells. They can develop just under the skin anywhere in the body, including the neck, back, arms, thighs, and shoulders.
Myxomas are benign tumors of the heart. They most often develop in the left atrium.
Symptoms can include:
They range in color from pink to tan or brown, and they can be raised or flat.
An osteoma is a benign tumor typically present in the long bones.
These tumors can cause pain and swelling.
Papillomas are benign growths that grow from epithelial cells in the milk ducts of the breasts, sinus cavities, voice box, feet, and skin.
Benign tumors are sometimes found during a self-check or when you are undergoing screening or imaging for another reason. Regardless of how the tumor is discovered, your doctor will order certain tests to figure out if it is cancerous.
Depending on where the tumor is, how it feels, and your medical history, this process might involve:
- imaging, such as a mammogram, an ultrasound, an X-ray, a CT scan, or an MRI scan
- blood tests to check for specific hallmarks of cancer
- a biopsy to look at the tumor cells under a microscope
If you suspect that you might have a tumor, either because you feel it or because you are experiencing other symptoms, it is important to contact a doctor straight away. A physical exam and medical tests are necessary to confirm the tumor as benign.
Also, even though benign tumors do not tend to be life threatening, some need treatment. This can involve surgical removal.
Doctors typically recommend treatment for a benign tumor if there is a chance that it will develop into cancer or if it is causing bothersome or potentially serious problems (or may do so in the future).
Sometimes, doctors recommend a watchful waiting approach, with routine follow-up visits and screening to see if a benign tumor grows, becomes problematic, or even disappears.
Possible therapies for benign tumors include medications, radiation therapy, and surgery.
Finding a benign tumor early, before it grows large, can improve the outlook — even if surgery is the preferred treatment.
Sometimes, having specific benign tumors linked to a genetic condition, such as NF1, can involve frequent screenings for related cancers. Generally, however, most benign tumors do not increase the risk of developing cancer.
Contact your doctor if you suspect that you have a tumor, if tumors run in your family, or if you find a lump or atypical growth during a self-exam. Also, call your doctor if you experience unusual symptoms that do not go away.
Benign tumors are typically not dangerous and can occur in many places in the body. They cannot spread, but they can grow large or grow in places that press on organs or other areas, such as parts of the brain.
Tumors that can lead to later consequences or cause harm often require treatment, which may involve surgery to remove them.
It is important to contact your doctor in a timely manner so that you can undergo testing to ensure that tumors are benign. The only way to know for sure whether it is cancer is to look at the tumor cells under a microscope.