Endoscopic ultrasound reliably identifies chronic pancreatitis when other imaging modalities have been non-diagnostic

There are classical radiological features for the diagnosis of chronic pancreatitis when utilising endoscopic retrograde cholangiopancreatography (ERCP), magnetic resonance cholangiopancreatography (MRCP) or computed tomography (CT), however, not all patients exhibit these features despite convincing clinical histories, which may result in diagnostic delay.

The aim of this study was to assess the use of endoscopic ultrasound (EUS) in the diagnosis of chronic pancreatitis when other imaging modalities had not yielded a diagnosis.

All patients undergoing pancreatic EUS between January 1996 and December 2004 were identified from the radiology computerised database. Sixteen patients with a clinical diagnosis of chronic pancreatitis (10 males, 6 females; mean age 53+/-4 years) underwent EUS after normal conventional imaging. Patients were then followed clinically until December 2007.

Thirteen patients exhibited features of chronic pancreatitis not identified by other modalities, which included duct dilatation (n=8), calcification (n=7); parenchymal change (n=6), irregular undilated ducts (n=2), pancreatic ductal calculi (n=1), and fine calcification (n=1). Of the remaining 3 patients, a diagnosis of autoimmune pancreatitis was made in one, in another there was a pancreatic duct stricture of uncertain origin that was stented, and in only one case was no diagnosis established. All 13 patients with an EUS diagnosis of chronic pancreatitis subsequently underwent a repeat CT scan for surveillance of their disease and in all cases, the CT scans subsequently demonstrated evidence of chronic pancreatitis indicating radiological progression. No new pancreaticobiliary diagnoses were established during this period.

EUS is a useful diagnostic tool confirming the diagnosis of chronic pancreatitis in 13 of 16 cases where histories were suspicious of chronic pancreatitis, and providing an alternative diagnosis in another two cases. EUS should be considered an important tool for diagnosis of chronic pancreatitis and should be used when cross-sectional imaging is non-diagnostic.