The significance of pancreatic ductal obstruction in differential diagnosis of the abnormal endoscopic retrograde pancreatogram.

Apparent obstruction of the main pancreatic duct was seen on the endoscopic retrograde pancreatogram in 50 patients. The final diagnosis was pseudocyst in 15, neoplasm in 15, chronic pancreatitis in 8, acute recurrent pancreatitis in 3, and abscess in 2. Seven patients were normal. This series emphasizes the broad differential approach necessary when confronted with ductal obstruction. Diagnosis is facilitated by accurate evaluation of the ductal and extraductal characteristics, especially the ductal detail at the point of termination.