Ischemic or toxic injury: A challenging diagnosis and treatment of drug-induced stenosis of the sigmoid colon

Figure 1 Colonoscopy and biopsy 14 mo ago. Electronic colonoscopy performed 14 mo prior to the ultimate hospital admission revealed smooth mucosa of the ileocecal junction and ascending colon (A1 and A2), nodular mucosal elevations in the transverse colon and descending colon (arrows, A3 and A4), severe mucosal congestion, erosion, and ulcer in the sigmoid colon (arrow, A5), and mild mucosal congestion, erosion and ulcer in the rectum (arrow, A6). Pathological analysis revealed chronic inflammation associated with necrosis (black arrow head, B1) and branching crypts (black arrow head, B2) in the mucosa of the sigmoid colon, as well as chronic mucosal inflammation and cryptitis (red arrow heads, B1 and B3)/eosinophil infiltration (black arrow head, B3) in the transverse colon. Hematoxylin and eosin staining; magnification of × 100 for B1 and B3, and × 200 for B2.