Budd-Chiari Syndrome: What Pathologists Need to Know About Hepatic Venous Outflow Obstruction

Hepatic venous outflow obstruction, known as Budd-Chiari syndrome, is a rare but significant cause of hepatic dysfunction. Worldwide, themost common cause of hepatic venous outflowobstruction is thrombosis of the hepatic veins and/or inferior vena cava secondary to an inherited or acquired hypercoagulable state (eg, factor V Leiden deficiency). Depending on the extent and acuity of the thrombosis, patients with Budd-Chiari syndrome may present in acute liver failure or as chronic compensated cirrhosis; almost all will have the classic (but nonspecific) pairing of abdominal pain and ascites. Histologic findings in the liver also vary according to the time course and magnitude of thrombosis and can range from zone 3 congestion to established cirrhosis. The cases reported herein demonstrate 2 variations of Budd-Chiari syndrome encountered in the daily practice of pathology. The aims of this review were to examine the clinical, radiological, and histologic features of Budd-Chiari syndrome and to discuss the differential diagnosis based on the observed histologic pattern.