Abstract
Small hepatic veins Budd-Chiari syndrome is a rare disorder characterized by hepatic venous outflow obstruction limited to the small intrahepatic veins, with normal appearance of the large hepatic veins at imaging. In this case only a liver biopsy can demonstrate the presence of a small vessels outflow block. Paroxysmal nocturnal haemoglobinuria (PNH) is one of the most severe acquired thrombophilic state and represents one of the main aetiological factors of Budd-Chiari syndrome. In patient affected by PNH with liver impairment and/or ascites, Budd-Chiari syndrome must be always taken into consideration and, if necessary, a liver biopsy performed to exclude the small hepatic veins involvement. We report a case of small hepatic veins Budd-Chiari syndrome secondary to paroxysmal nocturnal haemoglobinuria.