Giant Inflammatory Polyps in Diverticular Disease Mimicking a Colonic Mass: A Potential Malignant Masquerader

BACKGROUND: Inflammatory pseudopolyps (IPPs) are a common manifestation in inflammatory bowel disease (IBD) with more cases reported with ulcerative colitis than Crohn’s disease. IPPs can grow to form large polyps which are called giant inflammatory polyps (GIPs). These polyps may cause an obstruction and form a mass-like lesion and surgical resection may be warranted.
CASE REPORT: A 65-year-old male without a previous history of IBD presented with abdominal discomfort, poor appetite, constipation, weight loss, and hematochezia. Due to the high suspicion of malignancy, a computed tomography (CT) scan was performed and showed a fixed lesion in the mid sigmoid colon highly concerning for a primary colon carcinoma, with scattered diverticula, and associated with elevated carcinoembryonic antigen (CEA). Colonoscopy was done but the scope could not be passed due to obstruction. Sigmoidectomy was performed which showed a huge noninvasive lesion, which looked like pseudopolypoid serpiginous mass as giant inflammatory polyp, with scattered diverticula. On microscopic examination, pathology showed a villous polyp with numerous inflammatory cells, without any dysplasia or carcinoma.
CONCLUSIONS: GIPs are rarely reported without a history of IBD. Diagnosis of GIPs can be very challenging, and surgery is sometimes indicated for definitive diagnosis.

Keywords: Colonic Neoplasms, colonic polyps, Diverticulum, Colon