Effectiveness of an Endoscopic Biopsy Procedure Using EUS-FNA and EMR-C for Diagnosing Adenocarcinoma Arising from Ectopic Pancreas: Two Case Reports and a Literature Review

Adenocarcinomas arising from the ectopic pancreas in the gastrointestinal wall are rarely described in the literature. In addition, obtaining an accurate preoperative diagnosis is difficult in most cases because these adenocarcinomas occur primarily in the submucosal layer and form submucosal tumors. Endoscopic ultrasonography-guided fine-needle aspiration and endoscopic mucosal resection with a transparent plastic cap-fitted panendoscope followed by a biopsy are useful for histological typing and making the differential diagnosis of adenocarcinoma, gastrointestinal stromal tumor, malignant lymphoma or other. These procedures represent the first step toward diagnosing ectopic pancreatic adenocarcinoma. We herein report two such cases with a review of the pertinent literature.