Foreign body granuloma
Foreign body granuloma has a non-immune mechanism. Foreign body granuloma is a reaction to exogenous materials (talc, suture material, parasites, oil droplets, wood, metals, silica, silicon) or endogenous (hail shafts, keratin, cholesterol, urates/goutous tophi), which are immunologically inert.
Microscopically, foreign body granuloma to suture material (nylon, silk) contains multinucleated giant cells, with haphazardly arranged nuclei. These giant cells are fused macrophages. The foreign body is birefringent, and sometimes may be visible by polarized light in the middle of the granuloma or inside the giant cells. These granulomas are non-necrotic. (HE, ob. x4)
Foreign body granuloma (suture material) (HE, ob. x10).