Vedolizumab in the treatment of immune checkpoint inhibitor-induced colitis: Two case reports

Figure 1 There was marked hyperemia and edema of the mucosa from ileocecum to rectum. Diffuse mucosal erosion and superficial ulcers were visible and the mucosa was brittle and easy to bleed when exposed. A: Terminal ileum mucosa was normal; B: Erosion and superficial ulceration in ileocecal mucosa; C: Hyperemia, edema, erosion, and superficial ulceration in descending colon mucosa; D: Sigmoid colon mucosa is brittle and prone to bleeding.

Figure 2 HE staining biopsy showed no atypia of intestinal mucosal glands but found slightly irregular crypt with branches, crypt inflammation and crypt abscess; infiltration of such inflammatory cells as interstitial neutrophils and plasma cells. A: Low power view 10 × cryptitis; B: Medium power view 20 × cryptitis; C: Low power view 10 × crypt abscess; D: Medium power view 20 × crypt abscess.

Figure 3 There were observed obvious hyperemia and edema in the colon and rectum mucosa and diffuse mucosal erosion, ulcers and bleeding. The ulcers were covered with white fur and the intestinal mucosa was brittle and prone to bleeding when exposed. A: Mucosal erosion, ulceration and marked errhysis of transverse colon proximal splenic flexion of colon; B: Diffuse ulceration with white fur in descending colon mucosa; C: Erosion and superficial ulceration in sigmoid colon mucosa.

Figure 4 HE staining biopsy showed crypt inflammation and crypt abscess, infiltration of inflammatory cells. A: Low power view 10 × cryptitis; B: Medium power view 20 × cryptitis; C: Low power view 10 × crypt abscess; D: Medium power view 20 × crypt abscess.

Figure 5 There were visible mucosal erosion and mucosal healing scars. A: Mucosal healing scar in transverse colon proximal splenic flexion of colon and still narrow intestinal stenosis; B: Diffuse erosion in descending colon mucosa; C: Healing scar in sigmoid mucosa.