Non-necrotizing granuloma

A cluster of epithelioid histiocytes, multinucleated giant cells and surrounding lymphocytic inflammation without central necrosis. It reflects a chronic granulomatous immune response to bacterial/fungal infections, foreign-body (surgical sutures, splinters, tattoo ink, dusts, metals), autoimmune (sarcoidosis, Crohn's disease, rheumatoid arthritis), or medications (NSAIDs, antibiotics).