Necrotizing pancreatitis with multifocal hepatic artery pseudoaneurysms: Diagnostic limitations and rare appearance of suspected IgG-4 related disease

IgG-4 related disease is an auto-immune fibroinflammatory disease that affects nearly all organs, most commonly being the pancreas and other retroperitoneal organs. Many mixed inflammatory and fibrotic processes are associated, including, but not limited to, autoimmune pancreatitis, tubulointerstitial nephritis, and retroperitoneal fibrosis. Due to the broad manifestations of this disease, multiple diagnostic paradigms have been proposed and are currently in use. A 60-year-old female presented to our Emergency Department with complaints of severe low back pain, epigastric pain, hypotension, and vomiting. Initial laboratory evaluation included a Leukocytosis, hyperglycemia, and elevated inflammatory markers. Initial imaging revealed acute necrotizing pancreatitis. These findings, alongside elevated IgG-4 titers obtained in the outpatient setting, suggested, somewhat classically, IgG-4 RD. This case report is written to showcase the rare development of multiple pseudoaneurysms and a medium-sized vasculitis within the hepatic arteries distal to the site of pancreatic inflammation.