Pancreatic Heterotopia: Masquerading as Malignancy - A 15-Year Single Institutional Surgicalpathology Review

Context Pancreatic heterotopia, the presence of pancreatic tissue anywhere outside of the anatomical pancreas, is rare and typically an incidental finding. This manuscript reports two index cases of unusual presentations of pancreatic heterotopia masquerading as malignant lesions. Case reports Case #1: Fifty-five year-old female with right upper quadrant pain was found to have a retroperitoneal tumor between the right kidney and liver. Case #2: Thirty-eight-year-old female with a 20-year history of right upper quadrant pain and pancreatitis was found to have an incidental jejunal mass. An intraoperative frozen section was ordered on these two patients for suspected malignancy. Frozen section analysis in both cases showed the presence of benign glandular tissue admixed with ducts in a typical lobular fashion consistent with benign pancreatic tissue, confirming pancreatic heterotopia. The two index cases were investigated and analyzed in detail with relevant review of the literature as available in PubMed and Medline. A fifteen-year retrospective computer-based histopathological surgical review was conducted in our laboratory and the results were analyzed in the context of evidence-based literature of pancreatic heterotopias. 153 pancreatic pathologies were identified of which the commonest lesion was adenocarcinoma (58.8%) followed by pancreatic heterotopia (10.5%), pancreatic neuroendocrine tumors (7.2%) and pancreatitis (7.2%). Conclusions Pancreatic heterotopia is rare and most often an incidental finding; however, occasionally patients may present with a mass suggestive of malignancy, leading to clinical diagnostic dilemmas. Awareness of this uncommon lesion is of particular importance at intraoperative frozen section analysis for lesions in atypical locations. Received April 4th, 2015-Accepted May 20th, 2015