Pancreatic Neoplasms: Intraductal Papillary Mucinous Neoplasms

Pancreatic Neoplasms: Intraductal Papillary Mucinous Neoplasms

Now encountered more and more commonly in major centers around the world, intraductal papillary mucinous neoplasms (IPMNs) have become a popular subject of investigation. Bernard et al. [20] reviewed their experience with 53 consecutive resections of IPMN from 1985 to 2000. Carcinoma was present in 62% (33/53) of tumors and was significantly less common (both intramucosal and invasive forms) in lesions isolated within branch ducts. IPMNs containing carcinoma were more likely to exhibit mural nodules. The authors concluded that lesions >30 mm, located solely in branch ducts and lacking mural nodules, had a very low chance of harboring in situ or invasive carcinoma (none found in lesions meeting these criteria). Thus, such patients could be considered for limited resection. IPMNs involving the main duct or having associated mural nodules have a greater chance of housing carcinoma and warrant more aggressive treatment.

Adenocarcinoma arising within an IPMN (Fig. 5) is associated with a more favorable prognosis than ordinary ductal adenocarcinoma. In a multi-institutional review, Maire et al. [21] analyzed the long-term outcomes in 73 patients who underwent pancreatic resection for IPMN with in situ (n = 22) or invasive carcinoma (n = 51). The overall median survival was 47 months, and the 5-year survival rates for IPMN-affiliated in situ or invasive carcinoma were 88% and 36%, respectively. Multivariate analysis showed that lymph node metastases were the only significant factor that independently worsened the prognosis. Disease recurred only in patients with invasive adenocarcinoma (28 patients [38%]), with 16 occurring in the pancreatic remnant, 7 in regional lymph nodes, and 21 in various distant sites. A comparison of survival rates for resected IPMN-carcinoma vs resected ductal adenocarcinoma revealed a better 5-year prognosis for IPMN-carcinoma (36% vs 21%, respectively, P = 0.03).