Budd Chiari Syndrome Secondary to Pernicious Anemia: An Acquired Thrombophilia

Abstract

Budd-Chiari Syndrome (BCS) results from obstruction of hepatic venous outflow and is frequently linked to prothrombotic conditions. Acquired causes such as vitamin B12 deficiency anemia due to pernicious anemia remain underrecognized. We describe a 61-year-old patient admitted with progressive abdominal distension, diffuse abdominal pain, and lower limb edema. Clinical examination revealed ascites, collateral venous circulation, and hepatosplenomegaly. Laboratory evaluation showed severe macrocytic anemia, low serum cobalamin levels, elevated homocysteine, and positive intrinsic factor antibodies, confirming pernicious anemia. Liver function tests indicated cholestasis and mild cytolysis. abdominal CT demonstrated hepatic vein thrombosis with caudate lobe hypertrophy and signs of portal hypertension. Extensive thrombophilia screening excluded myeloproliferative neoplasms and antiphospholipid syndrome. The patient was managed with low-molecular-weight heparin followed by oral anticoagulation, in association with parenteral vitamin B12 supplementation and diuretic therapy. Clinical follow-up showed improvement of ascites, regression of collateral circulation, and stabilization of liver function after several months. This case underlines the role of pernicious anemia as a reversible acquired thrombophilia. Cobalamin deficiency induces hyperhomocysteinemia, which is prothrombotic and may trigger hepatic venous obstruction. Identifying this mechanism is clinically relevant, since targeted correction with vitamin B12 can reduce thrombotic risk in addition to anticoagulation. Portal hypertension in this patient was therefore not only a consequence of venous outflow obstruction but also a marker of delayed diagnosis. Early diagnosis and cobalamin replacement, in combination with anticoagulation, can improve clinical outcomes and prevent recurrence by correcting a reversible prothrombotic state.