PNH-driven hepatic vein thrombosis: A case of budd-chiari syndrome in disguise“

Abstract Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare clonal hematopoietic stem cell disorder characterised by complement-mediated intravascular hemolysis, bone marrow failure, and a pronounced risk of thrombosis. Budd-Chiari Syndrome (BCS), defined by hepatic venous outflow obstruction, is a severe and potentially fatal manifestation of thrombotic PNH. We present the case of a 26-year-old female with progressive abdominal distension, dull right upper quadrant pain, and morning haemoglobinuria. Clinical and laboratory investigations, including flow cytometric analysis using FLAER and CD55/CD59 staining, confirmed classic PNH with large granulocyte and monocyte clones and hepatic vein thrombosis consistent with BCS. This case underscores the diagnostic challenge posed by atypical thrombotic events in young patients and highlights the importance of early recognition and targeted therapy. Prompt diagnosis and initiation of complement inhibition therapy, such as eculizumab, can significantly improve prognosis. PNH should be considered in the differential diagnosis of young patients presenting with unexplained thrombotic phenomena and intravascular hemolysis.