[Characteristic findings of endoscopic retrograde pancreatography in the diagnosis of chronic pancreatitis with inflammatory mass].

Chronic pancreatitis with inflammatory mass (CPM) is difficult to differentiate from pancreatic cancer. To clarify the characteristic findings of CPM, we performed endoscopic retrograde pancreatography (ERP) in 39 patients. The pancreatogram showed smooth stenosis at the site of the mass in 26/39 cases (66.6%), irregular stenosis in 6 (15.4%), obstruction in 4 (10.3%), and no stenosis in 3 (7.7%). In the case of stenosis on ERP, the length of the stenosis correlated with the size of the mass. The pancreatogram distal to the mass showed dilatation in 26/35 cases (74.3%), 18 (51.4%) of which were simple dilatation. A follow-up study of 5 cases showed that all the stenoses had remained, and that the pancreatitis was aggravated in 2 cases. These findings suggest that CPM causes local stenoses of the pancreatic duct in many cases, and consequently may aggravate the stage of chronic pancreatitis.