Clinicopathological features of malignant intraductal papillary mucinous tumors of the pancreas: the differential diagnosis from benign entities.

Abstract

The accurate differential diagnosis of malignant intraductal papillary mucinous tumors (IPMTs) of the pancreas from benign IPMTs remains unclear. Predictive factors for differentiating malignant IPMTs from benign IPMTs can be documented. Retrospective study (1999-2003). Wakayama Medical University Hospital, Wakayama, Japan. Twenty-seven consecutive patients with IPMTs (11 with adenoma, 3 with dysplasia, 5 with adenocarcinoma, and 8 with invasive adenocarcinoma) who underwent surgery were retrospectively analyzed in terms of clinicopathological features. Clinical data, preoperative imaging findings, cytology, and tumor marker level, including carcinoembryonic antigen (CEA) and carbohydrate antigen (CA19-9), in serum and pure pancreatic juice. In preoperative imaging findings, the mean tumor size for the malignant IPMT group (81 +/- 18 mm) was significantly larger than that for the benign IPMT group (31 +/- 4 mm) (P =.002). The mean mural nodule size for the malignant IPMT group (9.8 +/- 4.4 mm) was significantly larger than that for the benign IPMT group (3.3 +/- 5.7 mm) (P =.002). The CEA levels in pure pancreatic juice in the malignant IPMT group (3051 +/- 7556 ng/mL) were significantly higher than in the benign IPMT group (41 +/- 80 ng/mL) (P =.003), although no significant differences in cytologic analyses and CA19-9 levels in pure pancreatic juice were found between the 2 groups. Our findings suggest that tumor size larger than 30 mm, mural nodule size larger than 5 mm, and CEA levels higher than 110 ng/mL in pure pancreatic juice were predictive factors for diagnosis of malignant IPMTs.