Surgical outcomes of noninvasive and minimally invasive intraductal papillary-mucinous neoplasms of the pancreas.

Background: Noninvasive and minimally invasive intraductal papillary-mucinous neoplasms (IPMNs) have a favorable surgical outcome. However, cases of recurrent noninvasive or minimally invasive IPMN are sometimes encountered, and the patterns of the recurrence of those tumors have not yet been fully clarified. In this study, we evaluated the surgical outcome of noninvasive and minimally invasive IPMNs, concentrating particularly on the pattern of recurrences.

Methods: Twenty patients with noninvasive and minimally invasive IPMNs were assessed. Resected specimens were evaluated histopathologically with regard to the malignant nature of the tumors, the status of the surgical margin, and peripancreatic lymph node involvement. Cumulative overall survival rates and recurrence after surgery were assessed.

Results: Of the 20 patients, 13 had benign IPMNs, including adenomas (n = 10) and borderlines (n = 3), and 7 had malignant IPMNs, including carcinomas in situ (n = 4) and minimally invasive IPMNs (n = 3). Histopathologic examination confirmed the absence of tumor involvement in the resected lymph nodes and at the surgical margins. During the follow-up period, one patient with minimally invasive IPMN and one patient with noninvasive IPMN died of tumor recurrence in the peritoneum that was presumably caused by intraoperative manipulation. All of the patients with benign IPMNs survived, whereas the 10-year survival rate of the patients with malignant IPMNs was 67%.

Conclusions: Surgical resection can offer a favorable outcome for noninvasive and minimally invasive IPMNs. Tumor recurrence was observed only in the peritoneal cavity. More careful perioperative management concerned with peritoneal recurrence should be emphasized for noninvasive and minimally invasive IPMNs.