Clinical Outcome of Surgically Resected Pancreatic Intraductal Papillary Mucinous Neoplasm According to the Marginal Status: A Single Center Experience

Background : Surgical resection is the treatment of choice of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. However, the benefit of clearing resection margin is still controversial. Methods : We reviewed 281 surgically resected cases of IPMN. The recurrences were compared according to the histologic grade (benign or borderline IPMN, malignant noninvasive IPMN, invasive carcinoma) and size (pancreatic intraepithelial neoplasia, PanIN, less than 0.5 cm in the long axis; and IPMN, greater than or equal to 0.5 cm) of the residual lesions at the resection margin. Results : Sixty cases (21.4%) were invasive carcinoma, and 221 (78.6%) noninvasive cases included 87(31.0%) benign, 107(38.1%) borderline and 11(3.9%) malignant noninvasive IPMN cases. In noninvasive IPMN, increased recurrence in patients with five or more years of follow-up was only related to the involvement of resection margin by severe dysplasia. The recurrence of invasive carcinoma was high (27.3%) even when the resection margin was clear, and was not related to the grade or size of residual tumors at the resection margin. Conclusions : Invasiveness is a strong risk factor for recurrence in IPMN regardless of the status of the resection margin. However, in noninvasive IPMN, histologic grading of residual lesions at the resection margin predicts local recurrence.