The “K-Sign”—A Novel CT Finding Suggestive before the Appearance of Pancreatic Cancer

Pancreatic invasive ductal adenocarcinoma (PDAC) has a poor prognosis, and the detection of PDAC during the early stage is thought to improve prognosis. In this study, we retrospectively investigated pancreatic morphological abnormalities that lead to the early diagnosis of PDAC with computed tomography (CT) imaging. In total, 41 out of 308 patients diagnosed with pancreatic cancer between 2011 and 2017 in our institution were enrolled. As a control group for the group with pancreatic cancer, 4277 patients without pancreato-biliary diseases were enrolled. We retrospectively reviewed and analyzed the clinical data including patient characteristics, the clinical course and preoperative CT imaging with pancreatic morphological features. Out of 41 patients, 24 patients (58.5%) showed local K-shaped constriction of the pancreatic parenchyma "K-sign" on preoperative CT images. Eight patients (19.5%) showed localized fatty change. Out of 4277 control patients, seven patients (0.16%) showed K-sign. "K-sign" may be used for the early diagnosis of PDAC by CT imaging.