An uncommon cause of pancreatitis with obstructive jaundice

A 56-year-old man with a history of diabetes mellitus poorly controlled recently (HbA1c: 7.5%, <6%) presented with a 3-month history of postprandial epigastric pain, 10-kg weight loss, steatorrhea, tea-colored urine, and clay-colored stool. Physical examination revealed yellowish skin and icteric sclera but no peripheral stigmata of cirrhosis. Laboratory investigation was significant for elevated aspartate aminotransferase (289 IU/L, 8-31 IU/L), alanine aminotransferase (613 IU/L, 0-41 IU/L), alkaline phosphatase (595 U/L, 34-104 U/L), γ-glutamyl transferase (758 U/L, 0-26 U/L), total and direct bilirubin (8.0/6.1 mg/dL, 0.3-1/0.03-0.18 mg/dL), and carbohydrate antigen 19-9 (289 U/mL, <37 U/mL). Contrast-enhanced computed tomography revealed diffuse enlargement of the pancreas (arrow) and dilatation of the common bile duct (CBD) without identifiable stone or a mass lesion (arrowhead; Figure 1A). Endoscopic ultrasound (EUS) demonstrated hyperechoic foci and strands in the enlarged pancreas (arrow) and layer-by-layer whole wall thickening with a hyper-hypo-hyperechoic series (sandwich pattern) of CBD (arrowhead) as well as gallbladder (star; Figure 1B). Magnetic resonance cholangiopancreatography (MRCP) showed dilated CBD with distal tapering near the pancreatic head (arrow; Figure 1C). The diagnosis of autoimmune pancreatitis was confirmed by serologic immunoglobulin G4 (IgG 4) elevation (IgG 4: 2880 mg/dL, 3-201 mg/dL) and favored type I according to nonductal Level 1/Level 2 criteria of international consensus diagnostic criteria.¹ The patient recovered from jaundice and gained weight after treatment of prednisone 40 mg/d for 4 weeks, then taper by 5 mg/wk. The 8-week follow-up EUS demonstrated normalization of pancreatic size (arrow) and CBD morphology (arrowhead; Figure 2).² Autoimmune pancreatitis mimicking pancreatic cancer is a rare cause of obstructive jaundice with an estimated incidence of 1 per 100 000.³ In summary, we demonstrated a case of autoimmune pancreatitis diagnosed by complement image study and elevating serum IgG 4, which achieved successful medical treatment of obstructive jaundice without further invasive procedures.¹

The authors declare no conflicts of interest.

This report was approved by the Research Ethical Committee of Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation (No. CR111-08).