The Clinical Indications for Limited Surgery of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Background There are many reports about limited surgery for intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. However, there is no consensus on limited surgery for IPMNs. The primary objective of this study was to define the clinical indications for limited surgery for IPMNs. Methods The data of 98 patients who underwent curative resections for IPMN were retrospectively analyzed. IPMNs were classified into four different pathological grades: low-grade dysplasia (LGD), intermediate-grade dysplasia (IGD), high-grade dysplasia (HGD), and invasive carcinoma (Inv-IPMN). Inv-IPMNs were divided into T1a, T1b, and T1c or over T1c (>= T1c). Based on preoperative radiological findings, IPMNs were stratified into the three groups using the 2012 International Consensus Guidelines: worrisome features, high-risk stigmata (HRS), and others. Results There were no positive lymph node cases and no recurrent cases of LGDs, IGDs, and HGDs. On the other hand, positive lymph node cases in T1a, T1b, and >= T1c were seen in 37.5, 20, and 22.2% of cases, respectively. The recurrence rates of T1a, T1b, and >= T1c were 50, 40, and 55.6%, respectively. Of the HRS cases, 30 (73.2%) were malignant and 25 (61%) were Inv-IPMN. HRS showed sensitivity of 92.6%, specificity of 77.5%, and accuracy of 81.6% to identify Inv-IPMN by preoperative imaging. Conclusions Limited surgery such as parenchyma-sparing pancreatectomy should be avoided for all cases of Inv-IPMNs, because every Inv-IPMN including T1a has the potential for lymph node metastasis and recurrence. HRS had high preoperative diagnostic ability for predicting Inv-IPMN. For cases that meet HRS criteria, pancreatectomy with lymphadenectomy is needed, and limited surgery should be withheld.