Brief Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. May 14, 2011; 17(18): 2332-2337
Published online May 14, 2011. doi: 10.3748/wjg.v17.i18.2332
Utility of pancreatography for diagnosing autoimmune pancreatitis
Kensuke Takuma, Terumi Kamisawa, Taku Tabata, Yoshihiko Inaba, Naoto Egawa, Yoshinori Igarashi
Kensuke Takuma, Terumi Kamisawa, Taku Tabata, Yoshihiko Inaba, Naoto Egawa, Department of Internal Medicine, Tokyo Metropolitan Komagome Hospital, Tokyo 113-8677, Japan
Yoshinori Igarashi, Department of Gastroenterology and Hepatology, Omori Medical Center, Toho University School of Medicine, Tokyo 113-8677, Japan
Author contributions: Takuma K and Kamisawa T contributed equally to this work, analyzed the data, and wrote the manuscript; Tabata T, Inaba Y, Egawa N and Igarashi Y collected the data.
Supported by The Research Committee on Intractable Diseases provided by the Ministry of Health, Labour, and Welfare of Japan
Correspondence to: Terumi Kamisawa, MD, PhD, Department of Internal Medicine, Tokyo Metropolitan Komagome Hospital 3-18-22Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan.
Telephone: +81-3-38232101 Fax: +81-3-38241552
Received: October 21, 2010
Revised: December 14, 2010
Accepted: December 21, 2010
Published online: May 14, 2011

AIM: To identify pancreatographic findings that facilitate differentiating between autoimmune pancreatitis (AIP) and pancreatic cancer (PC) on endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance cholangiopancreatography (MRCP).

METHODS: ERCP findings of 48 AIP and 143 PC patients were compared. Diagnostic accuracies for AIP by ERCP and MRCP were compared in 30 AIP patients.

RESULTS: The following ERCP findings suggested a diagnosis of AIP rather than PC. Obstruction of the main pancreatic duct (MPD) was more frequently detected in PC (P < 0.001). Skipped MPD lesions were detected only in AIP (P < 0.001). Side branch derivation from the narrowed MPD was more frequent in AIP (P < 0.001). The narrowed MPD was longer in AIP (P < 0.001), and a narrowed MPD longer than 3 cm was more frequent in AIP (P < 0.001). Maximal diameter of the upstream MPD was smaller in AIP (P < 0.001), and upstream dilatation of the MPD less than 5 mm was more frequent in AIP (P < 0.001). Stenosis of the lower bile duct was smooth in 87% of AIP and irregular in 65% of PC patients (P < 0.001). Stenosis of the intrahepatic or hilar bile duct was detected only in AIP (P = 0.001). On MRCP, diffuse narrowing of the MPD on ERCP was shown as a skipped non-visualized lesion in 50% and faint visualization in 19%, but segmental narrowing of the MPD was visualized faintly in only 14%.

CONCLUSION: Several ERCP findings are useful for differentiating AIP from PC. Although MRCP cannot replace ERCP for the diagnostic evaluation of AIP, some MRCP findings support the diagnosis of AIP.

Keywords: Autoimmune pancreatitis, Pancreatic cancer, Endoscopic retrograde cholangiopancreatography, Magnetic resonance cholangiopancreatography