A granuloma is a small area of inflammation in tissue, often formed in response to infection, irritation, or foreign substances. It consists of a collection of immune cells, primarily macrophages, that cluster together to isolate and contain the offending agent. Granulomas can occur in various parts of the body, including the lungs, skin, and lymph nodes. These structures are commonly associated with conditions such as tuberculosis, sarcoidosis, and certain autoimmune diseases. While granulomas are typically benign, they can sometimes lead to tissue damage or scarring if they persist over time. Diagnosis often involves imaging studies and biopsy to determine the underlying cause.