Giant cells

Multinucleated, often phagocytic cells formed when individual macrophages fuse together to isolate an invader or resolve inflammation. Often seen in granulomatous inflammation (tuberculosis, fungal infections, syphilis, giant cell arteritis/temporal arteritis, sarcoidosis, giant cell myocarditis), foreign-body reactions (retained sutures after surgery, glass), highly aggressive carcinoma/sarcoma, and osteoclastoma.