Pancreatic adenocarcinoma arising in intrahepatic pancreatic heterotopia

Abstract

Pancreatic heterotopia, also known as ectopic pancreas, accessory pancreas, or pancreatic rest, is defined as pancreatic tissue occurring in anatomic locations lacking geographic and vascular connections with the eutopic pancreas. Any physiologic process that occurs in normal pancreatic tissue may occur in pancreatic heterotopia, including, although rarely, malignant transformation. For this reason, any significant change in a lesion with imaging should prompt further investigation including obtaining tissue for pathologic evaluation. Histomorphologic criteria are essential in diagnosing malignancy arising in pancreatic heterotopia and include location of the tumour within or near the ectopic pancreatic tissue; the heterotopia must consist of acinar, epithelial and ductal elements; and there must be a clear transition from heterotopic to malignant tissue, preferably, an in-situ component.