Marked eosinophilia as the first manifestation of sclerosing cholangitis

We encountered a 45-year-old man who presented with marked eosinophilia as the first manifestation of sclerosing cholangitis. He was found to have a liver dysfunction during a regular physical check up and thereafter consulted our hospital. The laboratory data on admission indicated an elevation of AST (96 IU/L), ALT (136 IU/L) and ALP (1,025 IU/L). Furthermore, the leukocyte count was 18,190/mm(3) and he also showed marked eosinophilia (54.5%, 9,914/mm(3)). There were no atypical findings in the eosinophils. Other diseases causing eosinophilia, including parasite infection, allergic disorders, hypereosinophilic syndromes, drug-induced eosinophilia, malignancies, etc. were all investigated and ruled out. A liver biopsy revealed marked eosinophilic infiltration in the portal area and interlobular bile duct injury. Magnetic resonance cholangiopancreatography (MRCP) demonstrated a slight dilatation of the left intrahepatic bile ducts, but no clear diagnosis could be made at that time. A follow-up liver biopsy and endoscopic retrograde cholangiopancreatography (ERCP) finally revealed a diagnosis of secondary sclerosing cholangitis due to eosinophilic cholangiopathy. According to previous Japanese reports, eosinophilia of more than 5% was reported in 39 of 142 (27.0%) primary sclerosing cholangitis (PSC) patients. Eosinophilic cholangiopathy could cause a condition mimicking PSC and it might be confused as PSC with eosinophilia. The literature contains only about 40 case reports on eosinophilic cholangiopathy, and therefore, to date little attention has been paid to this condition. We should therefore pay attention to this condition when making a differential diagnosis of either PSC or IgG4-related sclerosing cholangitis.