Budd-Chiari Syndrome Secondary to Myelofibrosis in a Patient With Polycythemia Vera: A 16-Year Disease Progression Case Highlighting JAK2 Mutation Pathogenesis

Budd-Chiari syndrome (BCS) is a rare, life-threatening condition often caused by myeloproliferative neoplasms (MPNs), with polycythemia vera (PV) and essential thrombocythemia being common culprits. Myelofibrosis (MF)-related BCS is rare. We report a 45-year-old male patient with a 16-year history of PV that progressed to MF in 2021 and then to BCS in December 2022. The patient presented with abdominal distension and hepatomegaly, and imaging confirmed hepatic venous outflow obstruction. Treatment included anticoagulation, diuretics, and transjugular intrahepatic portosystemic shunt. This case highlights the delayed progression from PV to MF and subsequent BCS and the thrombotic risks in advanced MPN subtypes.