Portal hypertension as presenting feature of a myeloproliferative disorder. Diagnosis and therapeutic dilemmas.

In some patients presenting with complications of portal hypertension, thrombosis of hepatic or portal veins is identified as the cause. Hepatic or portal vein thrombosis may be secondary to recognized etiologies like infection or malignancy. When no etiology for the thrombosis is found, it is likely that a 'latent' myeloproliferative disorder (MPD) is the underlying abnormality. We present seven patients referred to us between 1988 and 1993 with complications of portal hypertension due to hepatic or portal vein thrombosis, in whom a 'latent', and in one patient overt, MPD was identified as the underlying disorder. Problems relating to the diagnosis of (latent) MPD in this subset of patients are discussed. The importance of in vitro 'endogenous' erythroid colony formation indicating the presence of MPD is emphasized. Also, a therapeutic strategy, with special emphasis on anticoagulation therapy, is suggested.