Abstract
A 67-year-old man referred for appetite and weight loss was found in laboratory data to have severe liver function disturbance and mild jaundice. Abdominal ultrasonography (US) showed common bile duct (CBD) dilation and a low echoic mass in the duct. Magnetic resonance imaging (MRI) showed a 2 cm nodule in the pancreatic head with low-intensity T1 and high-intensity T2. Magnetic resonance cholangiopancreatography (MRCP) showed common bile duct to be obstructed by a smooth stone-like mass. Celiac arteriography showed pancreas-head tumor staining without encasement. These findings suggested a malignant bulging pancreatic head tumor intruding into the common bile duct, necessitating pancreatoduodenectomy. Surgical findings showed a pancreatic head tumor that had grown intraductally into the common bile duct. Histological findings showed tumor cells with acinar patterns, and the common bile duct tumor resembled the prior specimen with an acinar pattern. Immunohistochemically, tumor cells showed positive staining for trypsin and lipase. Based on these histological findings, we made a definitive diagnosis of acinar cell carcinoma of the pancreas.
