Can ischemic colitis be differentiated from C difficile colitis in biopsy specimens?
Pseudomembranous colitis is often caused by Clostridium difficile; however, it may also be due to ischemia. To determine if any histologic features could be used to differentiate C difficile from ischemia, 49 biopsies of pseudomembranous colitis (25 from patients with C difficile colitis and 24 from patients with ischemic colitis) were coded, randomized, and evaluated for the presence of numerous variables, including the amount and distribution of mucosal necrosis, lamina propria hyalinization, and atrophic “micro-crypts.” Hyalinization of the lamina propria was seen in 19 cases of ischemia but not in C difficile colitis (p < 0.0001). Atrophic-appearing micro-crypts were seen in 18 ischemic cases and 6 C difficile cases (p < 0.0006). Lamina propria hemorrhage, full-thickness mucosal necrosis, and a diffuse microscopic distribution of pseudomembranes were significantly more common in ischemia than C difficile. Endoscopic examination identified pseudomembranes significantly more often wi
