Serial analysis of JAK2 mutation in a patient who developed essential thrombocythemia after orthotopic liver transplantation

A 52-year-old man developed essential thrombocythemia (ET) with JAK2 V617F mutation after orthotopic liver transplantation (OLT). Retrospective analysis showed that, despite a low platelet count, the JAK2 mutation was already found at presentation 14 months before OLT. The high platelet count that would have been typical of ET might be masked by the cirrhosis-related hypersplenism. Thrombocythemia became obvious after OLT. The patient subsequently developed blastic transformation 12 months afterward, a process probably accelerated by the immunosuppression required for the OLT.