A 30 year old man presents with jaundice and epigastric pain radiating to the back for 3 weeks. There is no history of anorexia, nausea or vomiting. He has not experienced similar symptoms in the past, and his medical, surgical and family histories are unremarkable. He only drinks socially, does not smoke, and denies drug abuse. A complete blood count reveals a hemoglobin level of 13.9 g/dL, and a leukocyte count of 10,600/mm3.
AST: 52 IU/L (10 - 34) ALT: 63 IU/L (10 - 40) ALP: 589 IU/L (44 - 147) Total Bilirubin 10.6 mg/dL (0.3 - 1.9) Direct Bilirubin: 8 mg/dL (0 - 0.3) Serum Lipase: 109 U/L (0 - 160) Serum Amylase: 30 U/L (23 - 85)
The pancreas is diffusely hypoechogenic. The liver and gallbladder appear normal. No gallstones are seen within the gallbladder. The extrahepatic biliary tree is not dilated.
The contrast CT scan of the abdomen reveals a sausage-shaped pancreas with delayed rim enhancement.
Serum IgG4 levels: 365 mg/dL (2.4-121.0)