MDCT of intraductal papillary mucinous neoplasm of the pancreas: evaluation of features predictive of invasive carcinoma.

Objective: The purpose of our study was to evaluate factors predictive of the presence of invasive carcinoma associated with intraductal papillary mucinous neoplasm (IPMN) of the pancreas on MDCT.
Materials and Methods: Preoperative MDCT of 36 consecutive patients (23 men, 13 women; mean age, 66.6 years) who had undergone surgical resection and had a pathologic diagnosis of IPMN were retrospectively assessed. CT was performed with a 4-MDCT scanner with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Arterial and venous phase images were acquired at 25 and 50-60 sec from the start of IV contrast administration. Type of ductal involvement, location, tumor size in branch duct type and combined type lesions, caliber of the main pancreatic duct, caliber of the common bile duct or common hepatic duct, and solid appearance of the lesion were assessed on CT and correlated with pathologic findings for invasive carcinoma.
Results: Pathologic analysis revealed carcinoma in situ in seven patients (19%) and invasive carcinoma in 15 patients (42%) arising from the IPMN. With invasive carcinoma, the size of the tumor in branch duct type and combined type, and the caliber of the main pancreatic duct were significantly larger compared with the lesions without invasive carcinoma (4.7 +/- 1.7 cm vs 2.6 +/- 1.4 cm [p = 0.0007] and 9.3 +/- 5.5 mm vs 4.6 +/- 4.1 mm [p = 0.006], respectively). A solid mass (p < 0.001), dilatation of the common bile duct or common hepatic duct (> or = 15 mm), and the presence of a stent (p = 0.0004) were correlated with the presence of associated invasive carcinoma.
Conclusion: MDCT helped to predict invasive carcinoma associated with IPMN.