Prognostic impact of pancreatic margin status in the intraductal papillary mucinous neoplasms of the pancreas

Background Intraductal papillary mucinous neoplasm (IPMN) of the pancreas often recurs after operative resection. The absolute risk and incidence of recurrence, however, especially in the remnant pancreas, is unknown. Methods We reviewed our 18-year experience of 144 surgical cases of IPMNs and selected 103 cases of benign IPMN and carcinoma in situ (CIS) for analysis of the clinicopathologic features and long-term outcome of the recurrent disease, with particular emphasis on the status of the cut margins of the pancreas. Results No patient with benign IPMN died within 5 years. Recurrences in the remnant pancreas were observed in 9 cases: 4 (4.9%) among the 81 cases of benign IPMNs and 5 (22.7%) among the 22 cases of CIS. All recurrences were considered as multicentric because none recurred at the true resection margin of the previous operative resection. The pancreatic transection margin was normal or hyperplastic in 64 patients, whereas adenoma was detected at the margin in 28 patients. The presence of adenoma had no influence on the outcome, and recurrence in the remnant pancreas was diagnosed in 5 (7.8%) of 64 adenoma-negative patients and 3 (10.7%) of 28 adenoma-positive patients. Furthermore, both overall survival and recurrence-free survival were similar between the 2 groups. Conclusion In benign IPMN and CIS, a favorable prognosis can be expected irrespective of the status of the pancreatic cut surface, although follow-up with adequate imaging studies is recommended for detection and resection of the recurrent disease.