We’re All Glad He Had the “Nerve:” A Curious Case of Abdominal Pain

Abstract

Introduction: Von Recklinghausen disease is a hereditary tumor syndrome. Only 5% of patients of NF 1 have symptomatic intra-abdominal manifestations, including neurogenic tumors, gastrointestinal stromal tumors, neuroendocrine tumors, and even adenocarcinomas. We are reporting a case of neurofibromatosis 1 presenting as a symptomatic small bowel tumor; an unusual presentation of a common but frequently misdiagnosed disease. Case Report: A 47-year-old male with no significant past medical history was referred to the gastroenterology clinic because of few months of left lower quadrant dull pain lasting for about an hour, no obvious exacerbating or relieving factors, no change in bowel habits, hematochezia, or weight loss. His physical exam and basic laboratory work were unremarkable. A computed tomography showed extensive wall thickening involving a long segment of distal and terminal ileum. His colonoscopy showed a large, irregular mass prolapsing in and out of the ileocecal valve; multiple biopsies were obtained, non-diagnostic. He eventually underwent surgical resection of the affected bowel segment; the final pathologic evaluation was consistent with neurofibromatosis. Upon further questioning during his clinic follow-up, the patient admitted to having a few cutaneous lesions removed in another hospital; he was told they were neurofibrmas, and on further dermatologic assessment, multiple cafe-au-lait spots were noted on the shoulders, thighs, and back. Discussion: Von Recklinghausen disease is one of the most common hereditary tumor syndromes. It is usually diagnosed at early age in the presence of typical mucocutaneous features along with a significant family history; but since up to 50% of cases are related to de novo mutations, this disorder is easily missed. Intra-abdominal tumors associated with NF-1 are divided into 4 types: 1) Neurogenic tumors (neurofibromas, gangliomas, gangliocytic paraganglioms, schwannomas), 2) gastrointestinal stromal tumors (GISTs), 3) neuroendocrine tumors (carcinoid tumors, somatostatinomas, insulinomas, and gastrinomas), and 4) adenocarcinomas. Only 5% of patients of NF 1 have symptomatic intra-abdominal manifestations; surgical resection is often required in theses cases, both to establish the diagnosis and to relieve the symptoms. Our case illustrates the significant under-recognition of NF-1 in the absence of typical family history, it also points out the important value of gastrointestinal findings to identify undiagnosed NF-1.