Acinar cell carcinomas with exophytic growth and intraductal pancreatic duct invasion: peculiar multislice computed tomographic picture.

On an ultrasound and multislice computed tomography (MSCT), a 76-year-old woman was found to have a huge mass lesion in the pancreatic head. MSCT showed 8.4 cm well-enhancing exophytic tumor of the pancreatic head which also protruded into the duodenum. A tongue-like protrusion into the main pancreatic duct was depicted. Laboratory data showed elevated carbohydrate antigen 19-9. Whipple's operation was performed. The pathological diagnosis was acinar cell carcinoma (ACC) originating in the pancreatic head and directly invading through the duodenal wall and the main pancreatic duct, without any lymph node involvement. A peculiar ACC with good enhancement, exophytic picture and tongue-like protrusion into the main pancreatic duct on MSCT is presented.