Abstract
A 12-year-old Japanese girl with pancreatic acinar cell carcinoma is presented. She was referred to our hospital with upper abdominal pain on exercise. Computed tomography scan showed a 17 × 17 × 12 cm heterogeneous mass in the right abdominal cavity centering around the pancreatic head to the anterior pararenal space. We performed pylorus-preserving pancreatoduodenectomy, because the tumor invaded the pancreatic head. Macroscopically, the tumor was a 19 × 18 cm, encapsulated mass derived from the pancreatic head without invasion to the surrounding organs, and consisted of solid and cystic portions. Histological examination showed tumor cells proliferating in an acinar pattern and invading the duodenal muscle layer. Immunohistochemically, tumor cells were positive for α1 trypsin and α1 chymotrypsin. From these histological findings, we diagnosed the lesion as an acinar cell carcinoma of the pancreas. We report this case of childhood acinar cell carcinoma, which is extremely rare, with a review of the literature.