Unusual Etiology of Budd-Chiari Syndrome in an Adolescent: A Case of Combined Thrombophilic Disorder.

Budd-Chiari syndrome (BCS) is an uncommon but potentially life-threatening hepatic vascular disorder resulting from obstruction of the hepatic venous outflow. While it predominantly affects adults, pediatric and adolescent presentations are rare, particularly those associated with inherited thrombophilia. Early diagnosis and appropriate intervention are essential to prevent complications such as portal hypertension, hepatic ischemia, and liver failure. We describe the case of a 15-year-old female who presented with progressive abdominal distension, right upper quadrant pain, and bilateral lower limb edema. Imaging studies, including ultrasound and contrast-enhanced CT, revealed hepatic venous obstruction with thrombus extension into the portal, superior mesenteric and splenic veins, and gross ascites. Laboratory findings indicated elevated inflammatory markers and impaired liver function. A detailed thrombophilia workup demonstrated deficiencies in protein C and antithrombin III and a Factor V Leiden mutation, confirming a hypercoagulable state as the underlying etiology. The patient was diagnosed with subacute Budd-Chiari Syndrome secondary to inherited thrombophilia. She was initiated on anticoagulation therapy with warfarin, later transitioned to rivaroxaban, and managed with diuretics and dietary modifications. Clinical improvement was achieved, and the patient was referred to a liver transplant center for ongoing evaluation.