Figure 3
From: Initial diagnosis of Wegener’s granulomatosis mimicking severe ulcerative colitis: a case report
A and B: Microscopical aspect of two arterioles with vasculitic changes. (A) Vessels are surrounded by dense histiocytic infiltrates forming, in many cases, granulomas. Many vessels also show platelet-rich thrombi associated to inflammatory changes of the wall. (B) The vascular wall shows large areas of fibrinoid necrosis with neutrophil granulocytes that were nearly complete destroyed. * lumen of the vessel; FN: fibrinoid necrosis; HIS: histiocytic infiltration; IN: intima; SM: smooth muscle; TH: thrombus.