Small Intrahepatic Vein Budd-Chiari Syndrome Complicated by Fusobacterium nucleatum Peritonitis.

Budd-Chiari syndrome is a rare disorder with significant liver-related complications. We present a 28-year-old woman with a 1-month history of weight loss and ascites. Hepatic venogram showed patent hepatic veins and inferior vena cava; however, there was an increased hepatic venous pressure gradient, which is clinically significant for portal hypertension. Hereditary and acquired thrombophilia workup was unrevealing. During admission, she developed peritonitis with Fusobacterium nucleatum and was treated with piperacillin-tazobactam. Liver biopsy showed vascular changes with features of venous outflow obstruction, and she was diagnosed with "small hepatic vein" Budd-Chiari syndrome. She was treated with transjugular intrahepatic portosystemic stent-shunt and tinzaparin, with significant clinical improvement.