S3047 Small Intestinal Adenocarcinoma: Rarely Considered, Often Missed on Endoscopy

Introduction: Tumors of the small bowel account for 5% of all tumors of the gastrointestinal tract. Of those tumors, 55-82% are in the duodenum, 11-25% in the jejunum, and 7-17% in the ileum. Adenocarcinoma of the small bowel is a challenge to diagnose due to the extended reach of gastroscope with most cases require multiple investigations. Often late presentation of patients leads to a poor prognosis. Early-stage small bowel tumors can be successfully treated surgically. Case Description/Methods: A 74-year-old man presented with complaints of progressively worsening bilious emesis after meals and epigastric abdominal pain for 2 months duration. Outpatient, he had esophagogastroduodenoscopy, nuclear medicine gastric emptying study, and CT enterography which were all unremarkable. Two weeks after his CT his symptoms continues to get worse and he could no longer tolerate any diet. Repeat CT was done showing obstruction in the jejunum. He underwent push enteroscopy where an apple core mass was seen in the proximal jejunum. Biopsy revealed invasive moderately differentiated small intestinal adenocarcinoma. He had CEA 3.1 ng/ml. He underwent laparoscopic duodenectomy with duodenojejunostomy leading to full recovery. His final pathological grade was T3N1M0 and a 2-month post-surgical PET CT showed no residual tumor. Discussion: The most common tumor of the small bowel is carcinoid tumor followed by adenocarcinomas, and these tumors are most frequent in patients with Crohn’s disease. The most common location for AC is the ileum. Small-bowel Neoplasms (SBN) pose substantial diagnostic and therapeutic challenges. SBN are usually incidentally discovered during the evaluation of occult Gastrointestinal Bleed, imaging, vs capsule endoscopy. Inaccessibility for routine flexible endoscopy causes a delay in diagnosis. In our patient multiple tests up to 2 weeks before the patient’s presentation were unremarkable. Push enteroscopy permits evaluation of the proximal small intestine to a distance that is approximately 50 to 100 cm beyond the ligament of Treitz. If there is no concern for obstruction wireless capsule endoscopy (CE) is a new, painless method of imaging the entire small bowel with great results. CT or MR enterography has a sensitivity of 60-70% and specificity of 90%. Mural features are predictors of active inflammation for both CT and MR enterography, while perienteric features can be distinguished better on CT enterography. Diagnosing Small Bowel Neoplasms (SBN) requires a high degree of suspicion.Figure 1.: CT enterography (top left), CT showing SBO and GOO (top right), Mass on Push enteroscopy (bottom left), and Adenocarcinoma pathology (bottom right).