A Guide to Adenoma

Medically Reviewed By Teresa Hagan Thomas PHD, BA, RN
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Adenomas are noncancerous tumors. They originate in the epithelial tissue covering your organs and glands. They tend to grow along your glandular organs and in many areas, including the adrenal, parathyroid, pituitary, or colon areas. Adenomas have the potential to become cancerous. Your doctor may choose to monitor an adenoma if it is nonfunctioning, meaning it is not producing hormones. If treatment is necessary, it may include medications or surgery.

Read on to learn more about the types, symptoms, and treatments for adenomas.

What are the types of adenomas?

A woman undergoing a CT scan
Bowery Image Group Inc./Stocksy United

There are two main types of adenomas based on their growth patterns:

Tubular: Tubular adenomas are tube-shaped and are less likely to develop into cancer than adenomas with villous growth patterns.

Villous: Villous adenomas have leaf-life or finger-like projections. Due to the fact that they have more surface area, they are more likely to become cancerous.

Tubulovillous adenomas have a combination of both growth patterns.

Where can adenomas develop?

Adenomas can grow in many parts of your body, commonly around the glands. These may include the:

  • adrenal glands, which sit above your kidneys
  • pituitary gland, which sits at the base of your brain 
  • parathyroid glands, which sit behind the thyroid gland at the base of your neck
  • salivary glands, which sit in three areas around your jaw

Adenomas can also grow in the lining of your colon. Doctors typically refer to these adenomas as colon polyps.

Other areas where adenomas may develop include the kidneys, breasts, appendix, skin, or prostate.

What are the causes of adenomas?

While the exact cause of adenomas is unknown, certain risk factors may increase your likelihood of developing adenomas:

Some genetic mutations or diseases, such as familial adenomatous polyposis, can trigger adenoma development.

What are the symptoms of adenomas?

Adenomas may not cause symptoms. However, depending on the type and size of an adenoma, you may experience symptoms such as:

Some adenomas — like pituitary adenomas — are asymptomatic unless they actively produce hormones.

How do doctors diagnose adenomas?

The type of adenoma will determine the exact tests required for diagnosis. In general, your doctor will assess your medical history and perform a physical examination. They may need various imaging tests — such as CT, PET, or MRI scans — to confirm a diagnosis.

In some cases, blood or urine tests may be necessary to check for atypical hormone levels or other blood markers.

If your doctor suspects colon polyps, they may need to perform a colonoscopy and take a tissue sample from the area of concern. A laboratory will analyze the tissue sample to determine if the mass is an adenoma or is cancerous.

What are the treatments for adenomas?

If an adenoma is benign and not causing any symptoms, your doctor may choose to monitor the situation with regular appointments. During successive appointments, your doctor will assess the size of the adenoma to make sure it does not grow or change.

If the adenoma causes an excess release of hormones, your doctor may prescribe medication to manage the release. For example, pituitary adenomas that secrete too much prolactin may require treatment with dopamine agonists.

Your doctor may recommend surgery to remove an adenoma if it is large or causes substantial health concerns.

What are some potential complications of adenomas?

One of the concerning potential complications of adenomas is that they may evolve into cancerous tumors. There are no definitive predictors to establish which adenomas will remain benign and which ones will become cancerous. So, your doctor will approach all adenomas with caution by assuming that they may be pre-cancerous tumors.

Even if an adenoma is noncancerous, it can cause other complications. Adenomas that become large may put pressure on nearby parts of the body, like the nerves.

Can you prevent adenomas?

Some adenomas cannot be prevented, such as those caused by genetic mutations or diseases. However, there are certain things you can do to lower your risk of developing adenomas caused by other factors. Try to:

  • Exercise regularly.
  • Eat a balanced diet.
  • Reduce your alcohol consumption.
  • Quit smoking.

What is the outlook for people with adenomas?

With proper monitoring and treatment, the outlook for people with adenomas is generally good.

Getting regular checkups and screenings are important for early diagnosis of an adenoma. The earlier the diagnosis, the better your chance of managing the adenoma and avoiding serious side effects or cancer.

Frequently asked questions

These are a few other commonly asked questions about adenomas. Dr. Teresa Hagan Thomas reviewed the answers.

How serious is an adenoma?

Adenomas are usually not serious. However, if they are large or produce excess hormones, they may cause symptoms and require treatment. In addition, adenomas can become cancerous. Regular checkups can reduce your risk of complications.

Do adenomas need to be removed?

If an adenoma is large, causes symptoms, or if your doctor thinks it has a high risk of becoming cancerous, you will probably need to have a healthcare professional surgically remove it.


Adenomas are benign tumors that commonly develop around your glands or in your colon. While the exact cause of adenomas is unknown, certain factors — like alcohol consumption, tobacco use, or inflammatory bowel disease — can increase your risk of developing them.

While many adenomas can be asymptomatic, larger or hormone-secreting adenomas can cause headaches, anemia, nausea, or vomiting. Doctors typically diagnose adenomas with blood or urine tests, imaging tests, or exploratory procedures like colonoscopies.

Some adenomas may not require immediate treatment. Others may need medications to help you manage symptoms and hormone levels. Doctors may also perform surgery to remove an adenoma.

Talk with your doctor if you have symptoms consistent with adenomas or if you want to screen for them. Regular checkups are important to help diagnose and manage adenomas.

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Medical Reviewer: Teresa Hagan Thomas PHD, BA, RN
Last Review Date: 2022 Jun 8
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