A granuloma is an area of tightly clustered immune cells, or inflammation, in your body. They form around an infection or foreign object in your body. They can form almost anywhere, but they’re most often found in your lungs. Granulomas can be a symptom of a chronic condition or an infection.
A granuloma is an area of inflammation (the way your body protects itself from something harmful) in your body. Granulomas are clusters of white blood cells that “wall off” bacteria, a foreign object or something else it thought was harmful from the rest of your body.
Granulomas most often form in your lungs, but you can have them in your liver, kidney, skin or almost anywhere else in your body.
A caseating granuloma has dead cells (necrosis) inside. If a granuloma contains dead cells, it gives your provider important clues about what caused it. Tuberculosis and some other infectious diseases cause caseating granulomas. Noninfectious causes (like sarcoidosis or foreign objects) create noncaseating granulomas.
Granulomas are more common in people with chronic (long-lasting) infections or inflammation, like tuberculosis, histoplasmosis or Crohn’s disease. People with sarcoidosis get granulomas for unknown reasons.
Granulomas on their own usually aren’t serious. They’re an immune response and aren’t cancerous. But sometimes, they’re a symptom of an underlying condition.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Granulomas often don’t cause symptoms on their own. For those who do have symptoms, they depend on where in your body the granuloma forms. You may also have symptoms of an infection that causes granulomas. Symptoms can include:
Granulomas on your skin are hard lumps that can be lighter or darker than the surrounding skin, often in shades of pink or purple. Sometimes, they’re painful to touch.
Under a microscope, granulomas contain cells that are tightly packed together, so it can be hard to tell where the edges of one cell ends and another begins.
Granulomas form when cells of your immune system (macrophages) aren’t able to destroy something they see as dangerous. This could be an infection (like bacteria or a fungus) or material your body doesn’t recognize (like stitches or a splinter in your skin).
Macrophages are special immune cells that “swallow” things that don’t belong in your body and destroy them. If they aren’t able to destroy something, it might trigger more and more immune cells to come to the area. They eventually form a tight cluster of cells.
Granulomas also sometimes form when your immune system overreacts and causes inflammation, even when there’s nothing to fight off. This can happen in some autoimmune disorders.
The most common infectious cause of granulomas is tuberculosis. But other bacterial infections, fungal infections, parasites and viruses can also cause granulomas, including:
Sarcoidosis, an illness where granulomas form for unknown reasons, is the most common noninfectious cause of granulomas. Other causes include:
Depending on where it is in your body, your provider may think you have a granuloma based on a physical exam or imaging (such as an X-ray, ultrasound or CT scan). The only way to know for sure if it’s a granuloma is for a provider to take a tissue sample (biopsy). A pathologist looks at the sample under a microscope to diagnose a granuloma.
As most granulomas are harmless, your provider may not do a biopsy right away. They may wait to see if it stays the same size or goes away on its own.
Providers don’t often treat individual granulomas. If you have an underlying condition that causes granulomas to form, your provider will treat you for that condition.
Depending on the cause, possible treatments for granulomas include:
If you have a painful granuloma, acetaminophen (Tylenol®) or ibuprofen (Advil®, Motrin®) might help. Ask your provider about what you can do to relieve your symptoms and whether it’s OK for you to take over-the-counter medications.
Most people can’t do anything to prevent granulomas. They’re a part of your body’s defenses. If you have an underlying condition, like an autoimmune disorder or a chronic infection, managing it will reduce your risk of developing granulomas.
Granulomas are usually harmless. They often go away on their own without treatment. Calcified granulomas (ones that have formed calcium deposits) might be less likely to go away. You may notice the same calcified granulomas noted on imaging reports over time. Even though they don’t go away, calcified granulomas that don’t change over time are often harmless.
Your provider can tell you what to expect if you have an underlying condition that causes granulomas to form. They can help you manage your symptoms if you frequently get granulomas.
The best way to take care of yourself is to manage any underlying conditions that cause granulomas to form. Talk to your provider about treating your specific condition.
See a provider if you:
You might want to ask your provider:
A note from Cleveland Clinic
Granulomas are part of your body’s natural defense system. Many people have them as lung nodules or bumps on their skin around a foreign object. They usually don’t need treatment and can go away on their own.
If you have certain conditions, like sarcoidosis or an autoimmune disorder, you may get granulomas frequently. Talk to your provider about any concerns you have. There may be additional options to help you manage your condition.
Last reviewed by a Cleveland Clinic medical professional on 01/11/2023.
Learn more about our editorial process.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy