Acute pancreatitis in intraductal papillary mucinous neoplasms correlates with pancreatic volume and epithelial subtypes.

ABSTRACT

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is associated with acute pancreatitis (AP) in some cases, however its causes have not been fully elucidated. We investigated the association of the incidence of AP with epithelial subtypes and pancreatic volume in IPMN. METHODS: This retrospective study included 182 consecutive surgically resected IPMN patients between January 2000 and December 2018. The relationship between the incidence of AP and epithelial subtypes of IPMN and pancreatic volume was investigated. Epithelial subtypes of IPMN were classified into gastric (G type N = 116), intestinal (I type N = 49), pancreatobiliary (PB type N = 14), and oncocytic types (O type N = 3). Pancreatic volume of the contrast-enhanced computed tomography scan was measured using Ziostation2 software. Histological pancreatic parenchymal atrophy was also evaluated. RESULTS: AP occurred more frequently in I-types (I-type vs. G-type, 22.4% [11/49] vs 3.4% [4/116], P = 0.003) and PB-types (PB type vs. G-type, 35.7% [5/14] vs. 3.4% [4/116], P = 0.007) in comparison with G-types, which constituted the majority of the resected IPMNs. AP occurred more frequently in I-type patients with high pancreatic volumes (I-type with high pancreatic volume vs. I-type with low pancreatic volume, 37.0% [10/27] vs. 4.7% [1/21], P = 0.02). However, histological atrophy did not show an additional influence on the association between the incidence of AP and epithelial subtypes. The elevation of serum pancreatic enzymes was not significantly related to epithelial subtypes. CONCLUSION: Epithelial subtypes and the degree of pancreatic volume may be closely associated with the incidence of AP in IPMN.