A 13-year-old girl presented with a 4-month history of a slow-growing, painless lump in her right upper abdomen but no other symptoms. On physical examination, we found a mass in the right hypochondrium extending to the epigastric and umbilical region that measured approximately 10 cm in diameter, was firm and globular, and was freely mobile in all directions, which made a clinical diagnosis extremely difficult. All of the measurable biochemical characteristics were within normal limits. Abdominal computed tomography was performed (Figure 1) and showed a large mass near the head of the pancreas. The patient underwent a laparotomy and the mass was removed during a Whipple procedure (Figure 2). She experienced an uneventful recovery and was discharged on the 10th postoperative day.