We hypothesized that bile duct biopsies might be more useful for diagnosing AIP and more closely reflect the histopathology of the pancreas than ampullary biopsies because the bile duct is commonly involved in AIP. Therefore, we carried out a clinicopathological study to examine the usefulness of endoscopic biopsies from Vater’s ampulla and the bile duct for discriminating

between AIP and PSC or pancreatobiliary cancers. The present find more study consisted of 26 AIP patients (all associated with cholangitis), 3 patients with IgG4-related sclerosing cholangitis (without AIP), 6 PSC patients and 27 pancreatobiliary carcinoma patients. Patients with AIP or IgG4-related sclerosing cholangitis were examined in a single disease group named IgG4-related sclerosing cholangitis (IgG4-SC). All patients were diagnosed and treated at Hokkaido University Hospital from April 2006 to February 2009. After excluding four AIP patients without cholangitis, all patients diagnosed with AIP, IgG4-SC, and PSC at our institute RG7420 were included in the present study. During the same period, we examined a total of 128 consecutive patients with pancreatic cancer and a total of 248 consecutive patients with bile duct cancer. Of the 128 patients with pancreatic cancer, 119 patients were excluded because of no biliary drainage (n = 5), no surgical treatment

(n = 94) or biliary drainage only (n = 20).

Of the 248 patients with pancreatic cancer, 230 patients were excluded because of no biliary drainage (n = 16), no surgical treatment (n = 67), biliary drainage only (n = 66) or transpapillary bile duct biopsy only (n = 81). All pancreatobiliary carcinoma patients MCE who underwent endoscopic retrograde cholangiopancreatography (ERCP) and ampullary and bile duct biopsies during this period were also included in the present study. The mean ages and male/female ratios were as follows: IgG4-SC, 68 years, 23/6; PSC, 44 years, 1/5; and pancreatobiliary carcinoma, 66 years, 22/5. The clinical presentations of patients with IgG4-SC included obstructive jaundice (13/29, 45%), mild abdominal pain (2/29, 7%) and bodyweight loss (1/29, 3%). Two patients (7%) were found to have elevated biliary enzymes based on a blood test. The remaining 11 patients (38%) did not have any subjective symptoms and were found to have abnormalities on a radiological examination for routine medical screening or follow-up for extra-pancreatobiliary diseases. PSC patients presented with serological liver dysfunction (4/6, 67%) and jaundice (2/6, 33%). Pancreatobiliary carcinoma patients had obstructive jaundice (21/27, 78%), elevated biliary enzymes (4/27, 15%), mild abdominal pain (1/21, 4%) and mild back pain (1/21, 4%).