Immunoglobulin G4-Related Disease Mimicking Unresectable Gallbladder Cancer
A 59-year-old man was referred to our emergency room with jaundice and right upper abdominal discomfort for 1 month. He complained of nausea, fatigue, loss of appetite, and yellowish discoloration of the skin. However, he did not complain of chilling sense and his body temperature was within normal limit.\nLaboratory data were as follows (values in parentheses indicate normal range): white blood cell count 7,780/mm3 (range, 4,000 to 10,000/mm3), hemoglobin 14.3 g/dL (range, 13 to 17 g/dL), hematocrit 40.1% (range, 39% to 52%), platelet count 233,000/mm3 (range, 130,000 to 400,000/mm3), asparatate aminotransferase 80 IU/L (range, 0 to 40 IU/L), alanine aminotransferase 138 IU/L (range, 0 to 40 IU/L), alkaline phosphatase 402 IU/L (range, 30 to 115 IU/L), total bilirubin 6.0 mg/dL (range, 0.2 to 1.2 mg/dL), direct bilirubin 5.0 mg/dL (range, 0 to 0.5 mg/dL), amylase 55 U/L (range, 30 to 100 U/L), lipase 60 U/L (range, 23 to 300 U/L), total protein 8.0 g/dL (range, 6 to 8 g/dL), albumin 4.3 g/dL (range, 3.3 to 5.2 g/dL), hepatitis B surface antigen negative, hepatitis B surface antibody negative, and urine bilirubin 3 positive (negative). The serum levels of carcinoembryonic antigen and α-fetoprotein were within normal limits; however, carbohydrate antigen 19-9 was 90 U/mL (range, 0 to 37 U/mL).\nAbdominal computed tomography (CT) revealed an infiltrative low density mass involving the neck portion of GB and adjacent hepatic parenchyma along with multiple radio-opaque gallstones in the fundus and neck portion (). However, there were not any abnormalities in pancreas and other organs on abdominal CT scan. As there was contiguous soft tissue infiltration involving the right and common hepatic artery, right and main portal vein, it was initially interpreted as unresectable GB cancer. The mass showed mild enhancement in the arterial phase and further delayed enhancement. In addition, there was diffuse symmetrical wall thickening of the extrahepatic bile duct and cystic duct. Magnetic resonance cholangiopancreatography (MRCP) revealed short segmental stricture at the proximal common hepatic duct with upstream bile duct dilatation (). Under the impression of GB cancer with direct hepatic invasion, ultrasonography-guided 18-gauge core needle biopsy was done at the hypoechoic lesion at S5 of the liver adjacent to the thickened wall of GB for pathologic confirmation. Histologic examination showed no malignant cells but only moderate periportal fibrosis with portal inflammation. In order to differentiate IgG4-related disease, we performed additional laboratory tests for autoimmune disorders as follows (values in parentheses indicate normal range): antinuclear antibody was negative: IgG 1,280 mg/dL (range, 700 to 1,700 mg/dL), IgA 381 mg/dL (range, 90 to 400 mg/dL), IgM 71.7 mg/dL (range, 45 to 230 mg/dL), IgG subtype IV 75 mg/dL (range, 6 to 121 mg/dL). Since the serum concentrations of autoimmune markers including the IgG4 were within normal range, the possibility of IgG4-RD was considered to be low. On our multidiscipline team conference this case was concluded as inoperable GB cancer. Therefore, biliary self expandable metal stent was inserted to treat the obstructive jaundice. After that, we took the biopsy once more in order to confirm the pathology. The microscopic examination of the second GB bed biopsy revealed diffuse lymphoplasmacytic infiltration and dense fibrosis (). Obliterative phlebitis and infiltration of some eosinophils were also found (). On immunohistochemical stain, the number of the IgG4+ plasma cells was counted up to 30/high power field (). Based on the characteristic findings of pathology, CT, and MRCP, the final diagnosis was IgG4-RD involving bile duct (SC), GB (cholecystitis), and hepatic parenchyma (inflammatory pseudotumor). And oral prednisolone therapy was started at a dose of 40 mg/day. After 4 weeks treatment it was tapered at 7 days interval with 5 mg dose. After total 11 weeks steroid treatment, it was stopped. And the symptoms had completely resolved without any complications. Abdominal dynamic CT after 4 weeks steroid treatment showed resolution of the hepatic mass lesion and decreased degree of GB wall thickening (). And the resolution state was maintained on follow-up abdominal CT after 11 months. The patient has been closely followed for 13 months in terms of recurrence and stent-related long-term complications, such as recurrent stone formation or stent obstruction due to epithelial hyperplasia.