Introducing “K-shaped sign”, a new finding on CT to detect a pancreatic cancer at the early state

Abstract

Introduction: We found and evaluated a specific change of the pancreas on CT just before a pancreatic cancer appears. Methods: We selected 32 patients among 241 patients with advanced pancreatic cancer. All 32 patients took abdominal CT more than one time, before their pancreatic cancers were diagnosed. Eight of the 32 patients underwent pancreatic resection.We reviewed all patients' abdominal CT and checked how abnormal findings appeared in the pancreas before finding their pancreatic cancer. Results: Twenty-three (71.8%) of the 32 patients had a localized constriction of the pancreatic parenchyma before appearing the pancreatic cancer. We named it “K-shaped sign” based on the figure. All of the 23 patients showed focal fatty changes around the area the K-shaped sign appeared. Four (17.3%) of the 23 patients had both K-shape sign and a partial main pancreatic duct dilatation. Nineteen of the 32 patients had a normal pancreas without focal fatty change on CT before the K-shaped sign occurred. Thirteen of the 32 patients had detected the K-shaped sign since the initial abdominal CT. All the 32 patients had the pancreatic cancer in the K-shaped sign's area. Conclusion: We introduced new CT finding before pancreatic cancer could be found, and named it “K-shaped sign” on CT. Although the “K-shaped sign” phenomenon has to be associated with early pancreatic cancer, it is unclear what the cause of the phenomenon is. When the K-shaped sign is observed on CT, the onset of a pancreatic cancer should be considered and determined by using more precise modalities.