By Crispin Musumba, MBChB, PhD, Edward Britton, MBBS, MRCP, and Howard Smart, MBBS, DM. Published previously in Gastroenterology (2013;144:274, 468-469).
A 50-year-old man presented with a 2-week history of intermittent epigastric pain. His pain typically started 1-2 hours after a meal and lasted for 10 minutes, with associated nausea and vomiting. On the day of admission, the pain had become severe and continuous (lasting 2 hours), exacerbated by lying flat, with accompanying jaundice and rigors. On examination, he was icteric and pyrexial (39.2 °C), with tenderness in the epigastrium and normal bowel sounds. Bloods tests revealed a hemoglobin count of 13.0 g/dL, leukocytosis (13 × 109/L), neutrophilia (13.0 × 109/L), elevated C-reactive protein (161 mg/L), alanine transaminase (424 U/L), alkaline phosphatase (230 U/L), gamma-glutamyl transpeptidase (579 U/L), bilirubin (77 mmol/L), albumin (32 g/L), glucose (7.4 mmol/L), amylase (375 U/L; normal, less than 150), and a normal lipid profile and calcium levels. Liver ultrasonography was unremarkable.
An abdominal computed tomography (CT) scan was done (Figure A). He was treated conservatively initially with intravenous morphine for pain relief and started on a course of intravenous antibiotics, with good clinical improvement. After improvement of his blood tests, he was discharged a week after admission, and had a magnetic resonance cholangiopancreatography (Figure B) performed as an outpatient. What is the likely diagnosis and pathogenetic mechanisms?