JAK-2 Positive Polycythemia Vera with Paroxysmal Nocturnal Hemoglobinuria and Splanchic Thromboses: A Case Report and Review of the Literature.

Abstract Background: Polycythemia vera (PV) is usually characterized by red cell mass expansion in the peripheral blood and can be complicated with thrombosis, bleeding, evolution to acute myeloid leukemia (AML) or a fibrotic phase. Paroxysmal nocturnal hemoglobinuria (PNH) in an acquired clonal haematopoietic stem cell disorder associated with chronic intravascular hemolysis, venous thrombosis, defective hematopoiesis, frequent episodes of infection and, rarely, leukemic transformation. Herein, we report an interesting case of a patient with co-existence of PNH clones and a JAK2V617F positive polycythemia vera, with unusual thromboses and not overt hemolysis.Case presentation: the case is a 51-year-old woman presented with increased levels of hematocrit and multiple liver, spleen, and left kidney infarctions with ascites; further investigation revealed a JAK2-positive polycythemia vera and a significant PNH population. Interestingly, our patient has experienced severe thrombotic events without reporting signs or symptoms of overt hemolysis.Conclusions: This case raises questions over uncharted aspects of the PNH etiopathogenesis, its potential association with myeloproliferative neoplasms (MPN) and highlights the difficulty of dealing with patients with more than one pro-thrombotic states, especially with established and severe thromboses.