Giant Pancreatic Acinar Cell Carcinoma: A Case Report and Review of Molecular Pathogenesis and Emerging Therapies

Pancreatic acinar cell carcinoma (ACC) is a rare pancreatic malignancy with molecular and clinical features distinct from pancreatic ductal adenocarcinoma (PDAC). We report a 58-year-old man with a 15-cm ACC of the pancreatic body and tail treated by distal pancreatectomy and splenectomy. Complete resection was achieved despite tumor size and surface fissuring suggestive of impending rupture. Operative time was 282 minutes with blood loss of 280 mL. Histopathology showed acinar architecture with B-cell lymphoma 10 (Bcl-10) positivity and nuclear beta-catenin accumulation, consistent with Wnt pathway activation. To clarify the biological differences between ACC and PDAC, we compared their molecular and clinicopathological features. Our analysis demonstrates that ACC's unique molecular profile and growth characteristics enabled successful surgical resection in this giant tumor. This case illustrates how systematic comparison of ACC with PDAC provides insights into the distinct biological behaviors of these pancreatic malignancies. We review current therapeutic advances in PDAC, including targeted therapies and immunotherapy approaches, which may inform future treatment strategies for ACC.