AB151. SOH24AB_229. Inflammatory fibroid polyp of the small intestine presenting as small bowel obstruction with intussusception: a case report and systematic review of the literature

Background: Intussusception is a rare in adults, accounting for only 1% of bowel obstructions. Of this small cohort however, a pathological lesion is found to act as a lead point in >90% of cases. Inflammatory fibroid polyp (IFP) has been previously termed 'the great mimicker' due to its close resemblance to invasive masses such as spindle cell tumours. Immunohistochemistry provides a useful means of definite subtyping with most IFP lesions staining positive for CD34 and, to a lesser extend vimentin and CD117. Case Description: A retrospective chart review was carried out following the presentation of a 74-year-old female to our department with acute intestinal obstruction. Computerized tomography (CT) scan of the abdomen and pelvis revealed a small bowel obstruction with intussusception secondary to an intramural mass lesion. The patient was treated with emergency laparotomy with segmental bowel resection and side to side anastomosis. A systematic review of the available literature was carried out using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Histopathological and immunohistochemical analysis demonstrated that the lesional cells stained positive for vimentin, SMA and CD34. Desmin, S100, cytokeratin DOG-1, C-KIT and ALK-1 were negative. These findings were consistent with IFP in terms of morphology and immunohistochemical profile. Twenty-four cases of IFP occurrence within the small bowel have been reported to date. Immunohistochemical profile was available in only 29% of cases (n=7). Conclusions: IFP can present in a diagnostically challenging manner. There is a lack of reporting of such benign tumours and their varied presentations within the small bowel from a surgical, histopathological and immunohistochemical perspective. This case report aims to add to the small body of research reporting on this topic.