Fistula formation into other organs secondary to intraductal papillary mucinous neoplasm of the pancreas: A case report and literature review

Introduction:Fistula formation from intraductal papillary mucinous neoplasm (IPMN) of the pancreas is uncommon; however, IPMN penetrating various organs has been increasingly reported. To date, there is a lack of literature reviewing recent reports and the clinicopathologic details of IPMN with fistula formation are still poorly understood. Methods:This study describes the case of a 60-year-old woman presenting with postprandial epigastric pain and diagnosed with main-duct (MD) IPMN penetrating to the duodenum, and presents comprehensive literature review of IPMN with fistulae. A literature review was performed using PubMed for all articles in English using predetermined search terms, including (fistula or fistulization), (pancreas or pancreatic or pancreato or pacreatico), (intraductal papillary mucinous), and (neoplasm or tumor or carcinoma or cancer). Results:A total of 83 cases and 119 organs were identified in 54 articles. Affected organs were as follows: the stomach (34%), duodenum (30%), bile duct (25%), colon (5%), small intestine (3%), spleen (2%), portal vein (1%), and chest wall (1%). Fistula formation into multiple organs was detected in 35% of cases. Approximately one-third of the cases had tumor invasion around the fistula. MD and mixed type IPMN accounted for 82% of cases. IPMN with high-grade dysplasia or invasive carcinoma were over three times more common than IPMN without these components. Discussion and conclusion:Based on the pathological examination of the surgical specimen, this case was diagnosed of MD-IPMN with invasive carcinoma and mechanical penetration or autodigestion was considered as the mechanism of fistula formation. Given the high risk of malignant transformation and intraductal dissemination of the tumor cells, aggressive surgical strategies, such as total pancreatectomy, should be recommended to achieve complete resection for MD-IPMN with fistula formation.