Ultrasound-Doppler diagnosis of Budd-Chiari syndrome. We report a case of apparently idiopathic Budd-Chiari syndrome, diagnosed by ultrasound and Doppler sonography, in a patient with latent myeloproliferative disease. This case proves that Doppler sonography shows in the hepatic veins a flow pattern suggestive of partial thrombotic obstruction. Moreover, we suggest that the search for a latent myeloproliferative disorder, by means of the spontaneous erythroid colonies formation in culture of bone marrow or blood mononuclear cells, should be routinely included in the diagnostic evaluation of each case of hepatic vein thrombosis without other recognizable causes. 