Invasive carcinoma derived from the nonintestinal type intraductal papillary mucinous neoplasm of the pancreas has a poorer prognosis than that derived from the intestinal type.

Abstract

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is divided into 4 subtypes: an intestinal type, a gastric type, a pancreatobiliary type, and an oncocytic type. The purposes of this study were to clarify the outcomes and the characteristics of invasive carcinoma derived from IPMN (invasive IPMC) by focusing on these subtypes with a comparison to conventional invasive ductal carcinoma (IDC) of the pancreas. A total of 30 patients with invasive IPMC were reviewed, and the tumors were divided into 2 pathologic subtypes, intestinal and nonintestinal type. The prognosis and characteristics of the 2 subtypes were evaluated. Furthermore, the prognosis of 119 patients with conventional IDC was compared with that of patients with invasive carcinoma derived from the intestinal or nonintestinal type IPMN. The 5-year survival rate of patients with the nonintestinal type (0.0%) was as poor as that of patients with conventional IDC (19.9%; P = .67). The patients with the intestinal type (66.7%) had a more favorable prognosis than patients with conventional IDC (P < .001). The nonintestinal type was characterized by positive lymphatic invasion and tubular invasive pattern. Invasive carcinoma derived from the nonintestinal type IPMN characterized by lymphatic invasion and tubular invasive pattern is associated with a poor prognosis.