Serous cystadenoma causing the double duct sign.

CASE REPORT: An asymptomatic 70-year-old man was found to have elevated liver function tests on a routine screening evaluation. Abdominal ultrasound revealed a pancreatic head mass. Magnetic resonance cholangiopancreatography confirmed a heterogeneously enhancing pancreatic mass that was suspicious for malignancy due to obstruction of the common bile duct and pancreatic duct. Consequently a pylorus-sparing pancreaticoduodenectomy was performed. Histology revealed a serous cystadenoma with scattered foci of PanIN III. DISCUSSION: Serous cystadenomas are benign tumors without significant malignant potential. Unlike pancreatic adenocarcinomas, these tumors tend to be slow growing, well-demarcated, and rarely, as in this case, produce a mass effect.