A 53-year-old woman came to the emergency department with three weeks of severe epigastric pain radiating to her back, intermittent vomiting, unintentional weight loss, and dark urine. She had a 30-pack-year smoking history. Imaging found a pancreatic mass, and her CA 19-9, a tumor marker heavily associated with pancreatic cancer, was significantly elevated.
Almost everything about the presentation pointed toward pancreatic ductal adenocarcinoma, a cancer usually caught too late for curative surgery. It was not cancer. Her IgG4 level was raised, and she responded to biliary decompression and corticosteroids, potentially avoiding extensive surgical intervention. On follow-up, both her CA 19-9 and IgG4 normalized.
