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

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.
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.
While the exact cause of adenomas is unknown, certain risk factors may increase your likelihood of developing adenomas:
- alcohol consumption
- high fat diet
- tobacco use
- acromegaly, a condition that causes the body to produce too much growth hormone
- inflammatory bowel disease
- urinary diversion, a procedure that opens up another pathway for urine to exit your body if your urinary tract is blocked or impaired
- bacterium linked to colorectal cancer, sepsis, and urinary tract infections that is called Streptococcus bovis
Some genetic mutations or diseases, such as familial adenomatous polyposis, can trigger adenoma development.
Adenomas may not cause symptoms. However, depending on the type and size of an adenoma, you may experience symptoms such as:
- headache
- fatigue
- dizziness
- iron deficiency anemia
- muscle weakness
- nausea
- episodes of vomiting
- abdominal pain
- rectal bleeding
Some adenomas — like pituitary adenomas — are asymptomatic unless they actively produce hormones.
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.
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.
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.
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.
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.
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.