granulomatoas

Granulomatous disease, or granulomatous inflammation, is a form of chronic inflammation characterized by granulomas—organized nodular collections of macrophages, often transformed into epithelioid cells, and frequently accompanied by multinucleated giant cells and a surrounding rim of lymphocytes. The granuloma forms as a defense to contain substances perceived as persistent irritants that are not easily eliminated.

Granulomas can be caseating (with a necrotic center) or non-caseating. They arise from a T helper 1–mediated immune response in many infectious and noninfectious diseases. Common infectious causes include Mycobacterium tuberculosis and fungal pathogens; noninfectious examples include sarcoidosis, foreign body granulomas, granulomatosis with polyangiitis, and chronic beryllium disease.

Clinically, involvement may affect lungs, lymph nodes, skin, and other organs depending on the disease. Diagnosis relies on histology showing granulomas, supported by microbiology, imaging, and tests to identify causative agents; special stains and cultures are used to detect bacteria or fungi, and serologic tests or imaging can help distinguish conditions such as sarcoidosis.

Treatment targets the underlying cause and may include antibiotics or antifungals for infections, corticosteroids or other immunosuppressants for inflammatory diseases, and removal of foreign material when feasible. Prognosis varies; for example, tuberculous granulomas require prolonged antimicrobial therapy, sarcoidosis often has a variable course, and some granulomatous diseases resolve while others persist as chronic conditions.