S3481 Small Bowel Obstruction Caused by Neurofibromatosis

Abstract

Introduction: We report an unusual case of acute small bowel obstruction in a woman with Neurofibromatosis type 1 (NF1) caused by numerous gastrointestinal neurofibromas. NF1 is an autosomal dominant genetic disorder that is classically characterized by the development of cutaneous neurofibromas, but less commonly, it is associated with a variety of gastrointestinal tumors including plexiform neurofibromas, mucosal ganglioneuromas, and gastrointestinal stromal tumors [1]. Up to 25% of patients with NF1 are reported to have a gastrointestinal tumor of some kind, but it is estimated that only 5% develop gastrointestinal symptoms including bleeding, abdominal pain, abdominal distention, constipation, and very rarely small bowel obstruction (SBO) [2]. Case Description/Methods: Patient is a 26-year-old female with a past medical history significant for poorly controlled Crohn’s disease who presented due to abdominal pain and hematochezia. Physical exam was notable for pain in the right upper quadrant. CT abdomen and pelvis with contrast showed high-grade small bowel obstruction with tethering of small bowel centrally concerning for active Crohn’s disease. Colorectal surgery was consulted and performed laparotomy with ileocecectomy and end ileostomy formation. The terminal ileum and cecum were sent to pathology for further analysis. The pathology report showed “wall thickening with extensive neural hyperplasia (ganglioneuromatosis) and plexiform neurofibromas. The features seen in the resection favor intestinal neurofibromatous proliferations with secondary chronic mucosal changes. There is no transmural inflammation, granulomas or other features typically seen in Crohn's disease.” (Figure) Discussion: This patient was initially thought to have SBO due to Crohn’s disease flare, but pathology report showed that the underlying cause was secondary to plexiform neurofibromas. A systematic review of the literature shows that this is a rare finding as only 25 cases were identified from 1972 to 2013 of NF1 patients who underwent laparotomy for SBO [2]. SBO is a rare but possible manifestation of NF1.Figure 1.: CT Abdomen / Pelvis showing high grade small bowel obstruction.