Ultrasonographic study on intraductal papillary mucinous tumors of the pancreas

Abstract

Objective To analyze the clinical and ultrasonographic features of intraductal papillary mucinous neoplasm (IPMN) of the pancreas and to assess the usefulness of transabdominal ultrasonography. Methods Twelve patients with IPMN underwent surgery, including 4 (33.3%)with adenoma and 8(66.7%) with adenocarcinoma. IPMN was classified into 3 categaries by the site of main duct,branch duct and combined type based on the ultrasonographic findings preoperatively. All the clinical presentations and the ultrasonographic imaging findings were analyzed and compared with the histologic diagnosis. Results Of malignant IPMNs,diabetes was presented in 5 cases,elevated CA19-9 was presented in 4 cases and steatorrhea was presented in 2 cases. But these was not presented in benigns. Transabdominal ultrasonography revealed all the cystic or cystic-solid lesions in this study. The mean diameter of the lesions with adenoma was (1.4 ± 0.8)cm (range,0.5 - 2.0 cm) and that with adenocarcinoma was (6.3 ± 6.0)cm (range, 2.0 - 20 cm). The mean diameters of the main duct for the cases with adenomas and adenocarcinomas were (1.0 ± 0.8) cm and ( 1.6 ± 1.0) cm, respectively. Among the adenomas, 3 cases were calssified as branch type and 2 were demonstrated with mural nodules and no colour signals was detected within them. Five of the malignancies were considered as main duct type and 3 were combined type. Seven cases were detected mural nodules and showed abundant colour flow signals within them. Conclusions Transabdominal ultrasonography revealed the pancreatic cystic lesions and dilated ducts of IPMN. Some characteristics should be considered for malignancy: clinical symptoms, tumor size and mural nodules with colour flow signals,which may be helpful for the diagnosis and management of IPMN. Key words: Ultrasonography; Pancreatic neoplasms; Adenocarcinoma,mucinous