A large inflammatory fibroid polyp of the colon treated by endoclip-assisted endoscopic polypectomy: A case report

Abstract

Inflammatory fibroid polyp is a rare benign polypoid lesion of the gastrointestinal tract. Histologically, inflammatory fibroid polyp is characterised by an admixture of numerous small vessels, fibroblasts and oedematous connective tissue, accompanied by marked inflammatory infiltration by eosinophils. A 40-year-old man visited our hospital for the purpose of colorectal screening due to a positive faecal occult blood test. A pedunculated and reddish polyp was found endoscopically in the ascending colon. The polyp was large but was resected endoscopically without any problems. Histologically, the abnormal tissue of the polyp was located in the submucosal and mucosal layer. Proliferation of spindle cells and infiltration of inflammatory cells, such as plasma cells and eosinophils, were observed. Immunohistochemically, the spindle cells were positive for CD34, which was localised in the cytoplasm. These cells were also positive for S100 protein but were negative for c-kit and muscle markers. These findings are compatible with the histological diagnosis of inflammatory fibroid polyp. The surgical margin of the polyp was free of the tumour. Inflammatory fibroid polyp is more commonly found in the stomach or small intestine, and rarely in the colon, and therefore our case is a rare example of large and pedunculated colonic inflammatory fibroid polyp, which was treated successfully by endoscopic polypectomy.