A granuloma is a cluster of white blood cells and other tissues that form in response to infections, inflammation, irritants, or foreign objects. They can appear in various parts of the body, including the lungs, skin, liver, kidney, and blood vessels. Granulomas are not cancerous. There are different types of granulomas, including:

• Foreign body granulomas: This type of granuloma develops when the immune system reacts to an object or irritant that penetrates the skin or eye, such as splinters, bee stings, spider bites, or injections.
• Skin granulomas: There are several types of granulomas that can affect the skin, including granuloma annulare and pyogenic granuloma.
• Lung granulomas: Granulomas are often found in the lungs and can be a symptom of a chronic condition or an infection, such as sarcoidosis, tuberculosis, or histoplasmosis.

Granulomas can be diagnosed through physical exams or imaging tests, such as X-rays, ultrasounds, or CT scans. Treatment depends on the underlying cause and may include medications, surgery, or watchful waiting. Anyone with a granuloma that does not get better on its own or keeps coming back should speak with a doctor.