The needle core sample this website showed markedly distended sinusoids filled with hematopoietic elements without an increase in blasts (Fig. 1B).
Extracted DNA from the liver showed a heterozygous JAK2 (Janus kinase 2) point mutation (Fig. 1C). These findings are diagnostic of involvement by the patient’s known JAK2-positive myeloproliferative neoplasm rather than compensatory EMH or infiltration by blasts. The increased hepatic blood flow resulted in high-output heart failure with a cardiac index of 6.4 L/minute/m2 (normal is <4.2 L/minute/m2) and significant cardiomegaly (Fig. 1A) without evidence of pulmonary hypertension.1 The shortness of breath improved under diuretic and inotropic management but respiration was still limited by anatomic constraints imposed by the hepatomegaly.
The case demonstrates the remarkable sequelae of long-standing PV driven by 3 decades of constitutive cellular proliferation associated with activation of signaling downstream of the erythropoietin/thrombopoietin receptor (Val617Phe [V617F]-mediated loss of Jak homology 2 pseudokinase [JH2]-autoinhibition in JAK2). Liver enlargement to this extent is uncommon in myeloproliferative diseases and progressed markedly following her splenectomy. The liver findings after splenectomy also reflect the end stage of a hematopoietic shift from the biopsy-proven fibrotic medullary cavity to the liver, where Obeticholic Acid the presence of the JAK2 mutation provides molecular evidence of a similar shift of the myeloproliferative clone to this site of embryonic hematopoiesis. Thereby, the findings combine components of existing theories of EMH discussed in the context of PV2 and myelofibrosis.3 Although a confirmatory bone marrow biopsy to demonstrate the requisite bone marrow fibrosis was not performed at the time of liver biopsy,
based on the leukoerythroblastic blood smear, this disease is medchemexpress best classified as post-polycythemic myelofibrosis and the high numbers of circulating blasts over the last 8 years (up to 28%) formally meet diagnostic criteria of blast phase.4 However, the stable clinical course over almost a decade suggests that circulating JAK2-positive blasts may not necessarily be a poor prognostic indicator in PV.5 Given the stability of disease and absence of infiltration of the liver by blasts, the high number of circulating blasts may not represent acute leukemic transformation, but rather progenitor cell trafficking at their new site of hematopoiesis.6 “
“In European populations, Budd-Chiari syndrome is almost always caused by thromboses in the hepatic veins. However, in Asian populations, membranous obstruction of the inferior vena cava is an important cause and can account for up to 40% of cases. The pathogenesis of membranous obstruction of the inferior vena cava is still debated. Some authors favor a congenital origin for the lesion as cases have been described in childhood.