IPMN Involving the Main Pancreatic Duct

Abstract

Objectives To describe the characteristics of intraductal papillary mucinous neoplasms (IPMNs) with predominant involvement of the main pancreatic duct (MPD), analyzing predictors for survival and recurrence. Background IPMNs involving the MPD harbor a high likelihood of malignancy and different biological features. The appropriateness of including cases with minimal noncircumferential MPD involvement has been challenged because these show clinicopathological features that are similar to branch duct IPMN. Accordingly, their exclusion has led to a redefinition of MPD IPMN (MD-IPMN). Methods Retrospective review of resected MD-IPMN from 1990 to 2013. All slides were reviewed by a single pancreatic pathologist and classified on the basis of epithelial type and invasive component. Results A total of 223 patients underwent resection for IPMN involving the MPD. Of these, 50 were excluded because of minimal MPD involvement. Among the 173 patients analyzed, median age was 68 years and 55% were males. Predominant epithelial phenotype was intestinal (50%). Forty-eight patients (28%) had low- or intermediate-grade dysplasia, whereas 125 (72%) had either high-grade dysplasia (33%) or invasive carcinoma (39%). Of the 67 invasive IPMNs, 39 were tubular carcinomas (58%) and invasion was minimal (<5 mm) in 28 (42%). The 5-year overall survival rate was 69% and the disease-specific survival rate was 83%. The estimated recurrence rate at 10 years was 25%. Size and type of the invasive component, lymph node positivity, and a positive resection margin were predictors for both survival and recurrence (P < 0.05). Conclusions MD-IPMN is mainly intestinal-type and malignant. After resection, it has a very favorable prognosis, especially in the absence of macroscopic invasive carcinoma.

Pancreatic resection for intraductal papillary mucinous neoplasm– a thirteen-year single center experience

“…The distribution of age in our cohort is similar to other surveys, with a wide range from 29 to 84 years [14, 20, 21] and no preponderance of male or female gender, as in other series [19, 22]. …”

Therapeutic Approach to Cystic Neoplasms of the Pancreas

“…Approximately 40%–70% of resected IPMN lesions will have either high-grade dysplasia or invasive carcinoma identified at the time of resection. [20, 21]…”

The Clinical Management of Main Duct Intraductal Papillary Mucinous Neoplasm of the Pancreas

“…The disease-free survival of resected invasive MD-IPMN is reported to be of 79 and 62% at 2 and 5 years [17], suggesting that postoperative surveillance should follow the scheme of ductal adenocarcinoma. With regards to IPMN-invasive types, tubular cancers have higher risk to have lymph node involvement [13, 38], whereas oncocytes tend to recur many years after pancreatectomy with good long-term prognosis even in case of surgical re-exploration [16].…”

“…In large surgical series, MD-IPMNs have been reported to harbor malignancy in more than 60% of the cases, with rates of invasive cancer of more than 40%. Of note, BD-IPMNs have a more indolent nature, with a malignancy rate in the same series of around 25% and of invasive cancer of 16% [7, 17]. It is important to underline that these notions are mainly driven from retrospective analysis of surgical series, generating a significant intrinsic bias.…”

“…In fact, minimal MPD involvement was frequently of the gastric type and the risk of high grade dysplasia and invasive carcinoma was only 11 and 6%, respectively, when compared to that of BD-IPMNs [19]. As a result, not all mixed type IPMNs should be categorized together, as the actual involvement of the MPD carries a different risk of malignancy [17]. …”