Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is rare disease which is steroid-responsive and often associated with IgG4 related systemic disease such as autoimmune pancreatitis. It is characterized by increased serum IgG4 and IgG4-positive lymphoplasmacytic infiltration in bile ducts. It is often difficult to distinguish IgG4-SC to hilar cholangiocarcinoma if it manifests as an isolated bile duct. We report a case of 79-year-old woman with IgG4-SC which was difficult to distinguish hilar cholangiocarcinoma due to similar clinical and radiologic findings, showing good therapeutic effect after a 2-week steroid trial.
Aged ; Bile Ducts ; Cholangiocarcinoma* ; Cholangitis, Sclerosing* ; Female ; Humans ; Immunoglobulin G ; Immunoglobulins ; Klatskin Tumor ; Pancreatitis ; Rare Diseases

The differential diagnosis of systemic lupus erythematosus (SLE) and autoimmune hepatitis (AIH) is difficult due to the resemblance of these two disorders. However, the accurate diagnosis is important for prognosis and treatment that are different from each other. We report a case of AIH-SLE overlap syndrome which tapering of prednisone and azathioprine therapy deteriorated the condition of a patient due to flare up of SLE. The patient was a 28-year-old woman diagnosed as AIH. After administrations of prednisone and azathioprine, her condition was improved. During dose reduction, she was admitted to our hospital as fever and dyspnea. She diagnosed as lupus nephritis. After high dose treatment with corticosteroids and azathioprine, she recovered. Once the diagnosis of autoimmune disease such as SLE or AIH has been made, clinicians should also be fully aware of concomitant other autoimmune disease.
Adrenal Cortex Hormones ; Adult ; Autoimmune Diseases ; Azathioprine ; Diagnosis ; Diagnosis, Differential ; Dyspnea ; Female ; Fever ; Hepatitis, Autoimmune ; Humans ; Lupus Erythematosus, Systemic ; Lupus Nephritis ; Prednisone ; Prognosis