Pancreatic duct strictures (PDS) and the utility of endoscopic ultrasonography (EUS)

Aim: To determine whether EUS can differentiate pancreatic cancer versus chronic pancreatitis in patients with isolated PDS or pancreatic duct obstruction (PDO). Methods: Our EUS databank (12192-12(95) was searched for patients that met the following criteria: PDS or PDO at ERCP. Exclusion criteria were: a history of bile duct abnormality, jaundice, chronic pancreatitis, alcohol abuse within the last 5 years, pancreatic mass or calcification detected at CT scan, or inadequate EUS examination. 14 patients (PDS-10, PDO-4) met these criteria. Results: 10114 patients had a history of either acute pancreatitis or acute relapsing pancreatitis. 9 patients had normal CT scans within 10 weeks of EUS examination, 5 had CT scans with equivocal readings of enlargement of the pancreas. EUS detected 5 pancreatic masses: 4 were pancreatic cancers (2 PDS, 2 PDO) and 1 that was suspicious for malignancy was benign at follow-up (1.5 yrs.). EUS was consistent with chronic pancreatitis in 5 patients (mean follow-up: 14 mos., range 6-24 mos.) and an acute inflammatory process in 1 patient (follow-up 15 mos.). EUS was normal in 3 patients. One patient with a normal EUS and CT examination underwent surgical exploration and intraductal papillary hyperplasia was detected. The 2 remaining patients with normal EUS exams are well: one was diagnosed with acute pancreatitis secondary to a medication (1 yr. follow-up) and the other diagnosis remains obscure (4 mos. follow-up). EUS provided an accurate diagnosis in 10114 (71%) patients with PDS or PDO: 4 malignant lesions and 6 chronic pancreatitis. Conclusions: 1. EUS can define the etiology of pancreatic duct abnormalities with reasonable accuracy when other imaging studies fail to delineate an etiology. 2. EUS is useful in the setting of clinical evidence of pancreatic disease, ERCP abnormalities and nondiagnostic CT scan.