Fig. 3
From: Sigmoid colon perforation in the patient with granulomatosis with polyangiitis
Pathological findings of the resected specimen. Histological sample of the colon shows ulcerative lesions and fibrinoid necrosis (a, hematoxylin and eosin [HE] staining, × 40). Fibrinoid necrosis and neutrophil infiltration of the small vessel (b, HE staining, × 200) and loss of vascular wall (c, Elastica van Gieson staining, × 200; d, cluster of differentiation 34 staining, × 200) are demonstrated