[Mesenteric and splenic vein thrombosis in a female patient with essential thrombocytosis and activated protein C resistance].

Splenic venous thrombosis is a rare disease in which an underlying hypercoagulable state can often be found. A 27-years old female patient with recurrent mesenteric venous and splenic thrombosis as a severe complication of an association of resistance to activated protein C and essential thrombocythemia is presented in this report. Establishing the diagnosis of essential thrombocytosis was particularly difficult because this was the case of the so called "silent" myeloproliferative disorder. The number of thrombocytes was almost normal before the splenectomy performed because of the splenic venous thrombosis. Thus, spontaneous growth of erythroid and megakaryocyte colonies in vitro and the clinical course of the disease were the clues for establishing the diagnosis, because the number of thrombocytes reached the values over 1500 x 10(9)/l after only 1.5 years of the follow-up. The case of this patient was interesting particularly from the surgical point of view because of the management strategy.