Segmental Diffuse Inflammatory Pseudopolyps Associated With Diverticulitis

Abstract

Abstract Introduction/Objective Inflammatory pseudopolyps (IPs) often develop in response to chronic active inflammation in patients with inflammatory bowel disease (IBD). IPs can be diffuse and numerous in severe IBD. IPs can also occur from other chronic active injuries, such as ulcers, persistent infection, ischemic colitis, anastomotic site and diverticulitis. IPs arising from diverticulitis is uncommon and generally few in numbers. We report a rare case of a patient with segmental diffuse IPs associated with diverticulitis in the absence of IBD. Methods A 59-year-old male patient with a history of sigmoid diverticulitis presented with abdominal pain and was treated with antibiotics. Three months later he had severe recurrent diverticulitis. CT scan showed wall thickening of the sigmoid colon and multiple sigmoid diverticula. Colonoscopy showed extremely severe inflammatory colitis in the area of diverticulitis between 25.0 and 35.0 cm from the anal verge. Biopsies revealed cryptitis, crypt abscesses, crypt architecture distortion and Paneth cell metaplasia. The patient underwent laparoscopic left colectomy. Results The rectosigmoid colon specimen is 18.0 cm in length and 6.0 cm in diameter. There was a 7.5 cm segment with numerous polyps. Multiple diverticula with diverticulitis were also identified in this region. The rest of the colon was unremarkable. Microscopic examination revealed numerous IPs and multiple diverticulitis. No evidence of IBD was identified. Conclusion To our knowledge, this is the first time that segmental and diffuse IPs are described with associated diverticulitis in the absence of IBD. The pathogenesis of IPs in non-inflammatory bowel disease is not well described. Previously, it was reported that diverticulosis and subsequent diverticulitis has no significant impact on the development of IPs, and IPs may arise independent of location and time of diverticulitis. Sporadic IPs may also appear without any underlying pathology. In the current case, there were multiple diverticula and diffuse diverticulitis, which may have contributed to the diffuse IPs. Further clinical inquiries revealed no clinical signs and symptoms of IBD.