Granuloma

A granuloma is a tightly packed cluster of white blood cells (inflammation) that forms a microscopic lump in your body. Your immune system forms it to “wall off” bacteria, a foreign object or something else it thought was harmful from the rest of your body. They most often form in your lungs, but you can have them in your liver, kidney, skin or almost anywhere else in your body.

Granulomas aren’t cancerous. And on their own, they’re usually not serious. But sometimes, they’re a symptom of an underlying condition.

Symptoms of granulomas

Granulomas usually don’t cause symptoms. When they do, it depends on where the granuloma forms in your body and how many you have. Symptoms could include:

• Lung: Shortness of breath, cough, chest pain or wheezing
• Eye: Vision problems, eye redness or pain
• Skin: Lumps, plaques and other types of rashes, on or below the surface of your skin
• Liver: Elevated liver blood tests

You may also have symptoms of an infection, like fever, swollen lymph nodes and night sweats.

What does a granuloma look like?

Granulomas on your skin can resemble many other rashes. They may look like lumps that can be lighter or darker than the surrounding skin. They’re often shades of pink or purple. They aren’t usually painful.

Granuloma causes

Infections and sarcoidosis are the two most common causes of granulomas. Some infections that can cause granulomas include:

• Tuberculosis (TB)
• Non-tuberculous mycobacteria
• Certain types of fungal infections

Other infections, foreign objects in your body, certain inhaled substances and reactions to medications can cause them, too.

Granulomas form when certain immune system cells (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.

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 cluster of cells.

Granulomas also sometimes form when your immune system overreacts and causes inflammation, even when there’s nothing to fight off.

Risk factors

Granulomas are more common in people with chronic (long-lasting) infections or inflammation, like tuberculosis, certain fungal infections or Crohn’s disease.

How doctors diagnose granulomas

Your provider may think you have a granuloma based on a physical exam or imaging (such as an X-ray, ultrasound or CT scan). Then, they might take a sample of tissue (biopsy) that’s examined under a microscope to make a diagnosis.

The type of granuloma can give your provider clues as to what’s causing it. Infections, like TB, cause necrotizing granulomas. Necrotic granulomas have dead cells inside. Non-infectious causes, like sarcoidosis, make non-caseating granulomas (without a core of dead cells inside).

Most granulomas don’t cause serious issues, so your provider might not do a biopsy right away. They may wait to see if it stays the same size or goes away on its own.

How are granulomas treated?

Providers don’t often treat individual granulomas. But if they cause problems with how your body works or are in a location that might cause harm, they might need to be treated. Many forms of granulomas from infections require treatment even if you only have a few.

Depending on the cause, possible treatments could include:

• Corticosteroids to reduce inflammation
• Immunosuppressants if you have an immune condition that’s causing granulomas
• Antibiotic, antifungal or antiparasitic medications to treat infections

When should I see my healthcare provider?

See a provider if you:

• Are concerned about an underlying condition that’s causing granulomas to form
• Have questions or concerns about the results of imaging, like on an X-ray or CT scan
• Have new or worsening symptoms, like fever or breathing problems

What can I expect if I have a granuloma-causing disease?

Granulomas from sarcoidosis usually won’t harm you. They often go away on their own without treatment. Sometimes, they become calcified (hardened). Calcified granulomas won’t go away, but they rarely cause any problems.

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 get granulomas frequently.