Inflammatory fibroid polyps of the duodenum: a review of the literature.

BACKGROUND/AIM An inflammatory fibroid polyp (IFP) is a rare benign submucosal gastro-intestinal lesion with an uncertain origin and natural history. An IFP was first described in the stomach and is rare in the duodenum. Presenting signs and symptoms vary according to anatomical site. This systematic literature review was prompted by the recent presentation of a patient with biliary obstruction caused by a duodenal IFP. METHODS A review of all duodenal IFPs identified in the PubMed database from 1971 onwards is presented within the context of what is known about the lesion at other gastro-intestinal sites. RESULTS Of approximately 1,000 IFP cases identified, 70% were of gastric origin, and fewer than 1% occurred in the duodenum. Duodenal IFPs typically present with non-specific features, and no pre-operative diagnoses of lesions at this site have been made. Microscopy reveals spindle-shaped cells, prominent capillaries, and an inflammatory cell filtrate. Immunohistochemistry shows the lesions to be CD34 and vimentin positive, but CD117, S100, and factor VIII negative. Local recurrence is most unusual following complete resection. CONCLUSIONS This rare benign entity in the duodenum should be included in the differential diagnosis of all peripancreatic masses. The advent of endoscopic ultrasound may allow pre-operative diagnosis of the lesion in the duodenum, enabling local resection and potentially avoiding unnecessary pancreatoduodenectomy.