A Rare Case of Polycythemia Vera Presenting as Chronic Liver Disease Due To Portal Vein Thrombosis
Fahad Qaisar
Keywords: Polycythemia vera, Masked polycythemia, Portal vein thrombosis, JAK2 mutation, Myeloproliferative neoplasms
INTRODUCTION:
Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders characterized by chronic proliferation of one or more myeloid lineages. Polycythemia vera (PV), essential thrombocythemia, and primary myelofibrosis constitute the Philadelphia chromosome–negative MPNs and may present with overlapping clinical and laboratory features.1 All MPNs carry a risk of progression to acute myeloid leukemia and are associated with significant thrombotic morbidity.2
Polycythemia vera is characterized by erythropoietin-independent erythrocytosis, frequently accompanied by leukocytosis and thrombocytosis. The JAK2 V617F mutation is present in more than 95% of patients and results in constitutive activation of the JAK–STAT signaling pathway.3 The World Health Organization (WHO) revised its diagnostic criteria in 2016 and reaffirmed them in 2022 to improve diagnostic sensitivity, particularly in patients with masked or early disease.4
DISCUSSION:
Polycythemia vera is associated with a high risk of thrombotic complications, which remain the leading cause of morbidity and mortality, affecting up to 40% of patients during the disease course.6 Thrombosis may be arterial or venous, with venous thrombosis frequently involving atypical sites such as the portal and splanchnic circulation.7
Masked PV is increasingly recognized and is characterized by normal hemoglobin and hematocrit levels, often due to iron deficiency or plasma volume expansion. Such patients may present late with thrombotic complications, as observed in this case.5,8 The presence of extensive thrombosis with elevated red cell count despite anemia should prompt evaluation for PV, including JAK2 mutation testing.
Keywords: Polycythemia vera, Masked polycythemia, Portal vein thrombosis, JAK2 mutation, Myeloproliferative neoplasms