A Rare Cause of Elevated Serum CA19-9.

Question: A 26-year-old woman without specific history presented to our hospital because of elevated serum CA 19-9 level for >3 years. She denied alcohol consumption or cigarette smoking. Moreover, no any surgical history or drug abuse was mentioned. She underwent a heathy check-up about 3 months ago. The marked elevation of serum CA 19-9 level was identified (1036 U/mL; normal range, <35 U/mL). She underwent esophagogastroduodenoscopy and colonoscopy, but these results were normal. Abdominal ultrasound examination, computed tomography scan, and magnetic resonance imaging also showed no gastrointestinal or pancreatobiliary tumors. Therefore, she visited our hospital for second opinion. Enteroscopy was suggested for further evaluation of the small intestine. On admission, physical examination revealed her abdomen was soft without tenderness or rebound on palpation. We prescribed antegrade double-balloon enteroscopy for her. Double-balloon enteroscopy demonstrated a 1.8 cm-sized subepithelial tumor with a nipple-like surface in the proximal ileum (Figure A). The subepithelial tumor showed soft consistency by forceps compression. Thus, we decided to resect it endoscopically. After submucosal injection of glycerol, the subepithelial tumor was resected by a polypectomy via an electric snare smoothly (Figure B). Three hemoclips were performed for the closure of postpolypectomy wound (Figure C). The resected tumor was sent for histopathologic study. No postpolypectomy bleeding or perforation was noted. What is your diagnosis of this subepithelial tumor in the small intestine? Look on page 32 for the answer and see the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Histopathologically, it demonstrated tumor consists of pancreatic ducts, acini, and islet cells (Figure D, hematoxylin and eosin staining, original magnification, ×20; Figure E, hematoxylin and eosin staining, original magnification, ×200). No active microorganism or malignancy was identified. Thus, a diagnosis of small intestinal heterotopic pancreas was made. Her serum CA 19-9 level decrease to 54 U/mL at 1 month later after endoscopic resection. Heterotopic pancreas is defined as a pancreatic tissue lacking vascular or anatomic continuity with the main body of the pancreas. It is an infrequent subepithelial tumor in the gastrointestinal (GI) tract. Although the incidence is rare, the stomach was the most common site of GI tract, followed by the duodenum and jejunum.1Chen H.L. Chang W.H. Shih S.C. et al.Changing pattern of ectopic pancreas: 22 years of experience in a medical center.J Formos Med Assoc. 2008; 107: 932-936Crossref PubMed Scopus (22) Google Scholar Heterotopic pancreas found in the ileum is a rare entity. The clinical manifestations of heterotopic pancreas may be asymptomatic; if symptomatic, it can manifest as abdominal pain, GI bleeding, intussusception, or pancreatitis.1Chen H.L. Chang W.H. Shih S.C. et al.Changing pattern of ectopic pancreas: 22 years of experience in a medical center.J Formos Med Assoc. 2008; 107: 932-936Crossref PubMed Scopus (22) Google Scholar When heterotopic neoplasm occurs, there may be a mild elevation in the serum amylase level or tumor markers. Small intestinal heterotopic pancreas is usually difficult to diagnose preoperatively. In the past, most cases of small intestinal heterotopic pancreas were diagnosed in laparotomies or autopsies.2Xiang S. Zhang F. Xu G. Ectopic pancreas in the ileum: an unusual condition and our experience.Medicine (Baltimore). 2019; 98e17691Crossref PubMed Scopus (2) Google Scholar Recently, a few cases of small intestinal heterotopic pancreas were diagnosed by deep enteroscopy or capsule endoscopy. Conventionally, surgical resection is the mainstay method for treating small intestinal heterotopic pancreas. However, endoscopic resection via deep enteroscopy is an alternative method.3Mickuniene R. Stundiene I. Jucaitis T. et al.A case of ectopic pancreas in the ileum presenting as obscure gastrointestinal bleeding and abdominal pain.BMC Gastroenterol. 2019; 19: 57Crossref PubMed Scopus (7) Google Scholar