PRIMARY SCLEROSING CHOLANGITIS IN AN ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY-NEGATIVE WOMAN: DIAGNOSTIC CHALLENGES IN A POSSIBLE ATYPICAL PHENOTYPE

Abstract

Primary sclerosing cholangitis is a rare chronic cholestatic liver disease characterized by inflammation, fibrosis, and multifocal stricturing of the intrahepatic and/or extrahepatic bile ducts. Although its diagnosis is usually supported by cholangiographic abnormalities and may be associated with immune-mediated conditions, atypical presentations without suggestive serological markers can delay clinical recognition. This report describes a 53-year-old woman with an uncommon presentation of primary sclerosing cholangitis, initially characterized by fever, severe abdominal pain, jaundice, acute pancreatitis with peripancreatic necrosis, persistent cholestasis, and recurrent episodes of severe acute cholangitis. The diagnostic investigation was challenging because autoimmune markers were negative, immunoglobulin G4 levels were normal, and magnetic resonance cholangiopancreatography showed only mild intrahepatic bile duct dilation without typical findings of primary sclerosing cholangitis. Definitive diagnosis was established only after endoscopic retrograde cholangiopancreatography, which demonstrated multifocal biliary strictures and irregularities compatible with the disease. The patient subsequently developed Tokyo grade III acute cholangitis, requiring intensive care, vasopressor support, broad-spectrum antibiotic therapy, and referral for liver transplantation assessment. This case highlights that primary sclerosing cholangitis may present with severe systemic manifestations, pancreatitis, negative autoimmune markers, and initially inconclusive noninvasive imaging. Persistent cholestasis of unclear etiology should maintain primary sclerosing cholangitis within the differential diagnosis, even in the absence of classical clinical, serological, or radiological findings. In selected cases, endoscopic retrograde cholangiopancreatography remains essential for diagnostic clarification and timely referral to specialized hepatology care.