INTRADUCTAL PAPILLARY TUMORS OF THE PANCREAS - EVALUATION WITH ENDOSCOPIC ULTRASONOGRAPHY

Background: We retrospectively analyzed the endoscopic ultrasonographi c characteristics of intraductal papillary tumors of the pancreas and identified signs indicative of malignant tumors. Methods: Twenty-eight patients with intraductal tumors and 38 with other pancreatic cystic lesions underwent endoscopic ultrasonography, conventional ultrasonogr aphy, and endoscopic retrograde cholangiopancreatography (ERCP). Resul ts: Intraductal tumors were classified into three subtypes, and endosc opic ultrasonographic characteristics were assessed. In main duct type tumors, the main pancreatic duct showed a segmental or diffuse modera te-to-marked dilatation, often associated with intraductal nodules. Pa ncreatic parenchymal atrophy was frequently recognized. Branch duct ty pe tumors consisted of multiple 5 to 20 mm cysts with the appearance o f a cluster of grapes. The main duct was mildly dilated or nondilated. Combined type tumors had features of both main duct and branch duct t ypes. Endoscopic ultrasonography (92%) differentiated pancreatic cysti c lesions more precisely than ultrasonography (82%) and ERCP (89%). Ma in duct or combined type tumors, large tumors (greater than or equal t o 30 mm for branch duct type), marked dilatation of the main pancreati c duct (greater than or equal to 10 mm for other types), and mural nod ules suggested malignancy. Endoscopic ultrasonography demonstrated the se signs more accurately than ultrasonography or ERCP. Conclusion: End oscopic ultrasonography is useful for diagnosing intraductal papillary tumors, particularly for predicting malignancy.