Pancreatic acinar cell carcinoma (ACC) is a rare neoplasm accounting less than 1% of malignant pancreatic tumors. A 47-year-old male patient visited the emergency room with epigastric pain. Computed tomography or magnetic resonance imaging revealed a 4.7-cm heterogeneously enhanced solid and cystic mass with internal necrosis located in the head of the pancreas. Radiological diagnosis was borderline malignancy such as neuroendocrine tumor or solid pseudopapillary neoplasm. Two months later, the necrotic mass in the pancreas head had grown up to 11 cm, compressing the duodenum, superior mesenteric vein, and proximal transverse colon. Pylorus preserving pancreatoduodenectomy with segmental resection of transverse colon was performed. Histopathological examination revealed that the tumor was pancreatic ACC. The patient recovered without any complication and was doing well without recurrence for 12 months after surgery.

Acute pancreatitis (AP) is an inflammatory disorder and the severity range from mild to severe form. The mortality of severe form of AP is still high despite of tremendous improvement of diagnostic modalities and therapeutic options. Although pathogenesis of AP is still not fully understood, autodigestion theory is regarded as an initial common pathophysiologic mechanism of AP for about 2 centuries. However, it is obscure which mechanisms are involving the disease severity. Upregulation of adhesion molecules, leukocytes, proinflammatory cytokines and chemokines are also concerned local injury, systemic exacerbation of inflammation and ultimately organ failure. In addition, transcription factor Nuclear factor-kappa B is also influence the severity through upregulate the proinflammatory genes. The patterns of acinar cell death are closely correlated with disease severity of AP. The degree of acinar cell apoptosis is reversed correlated whereas necrotic cell death is proportionate to severity.