Ectopic Pancreatic Tissue and Ectopic Pancreatitis

Ectopic pancreatic tissue due to aberrant embryologic development presents a diagnostic dilemma for the radiologist, particularly in the context of evaluating malignancy. On CT and MRI, ectopic pancreas parallels the imaging appearance of orthotopic pancreas, but confident distinction from other neoplastic and nonneoplastic entities remains challenging, especially when a pathologic process such as pancreatitis involves the ectopic tissue. We present a case of a 57-year-old woman with pulmonary artery sarcoma who presented with a perijejunal mesenteric mass initially described as metastasis. Further review of the patient’s imaging revealed previously present ectopic pancreatic tissue at this site, with an episode of ectopic pancreatitis mimicking metastasis. Identifying ectopic pancreatic tissue on routine imaging is crucial to alert subsequent readers, eliminate unnecessary workup, and limit patient anxiety. Although comparison examinations and clinical context are most important, imaging features that follow those of normal pancreas can be helpful for identification of ectopic pancreas.