JAK2+ Essential Thrombocythemia in a Young Girl With Budd-Chiari Syndrome: Diagnostic and Therapeutic Considerations When Adult Disease Strikes the Young.

A 12-year-old female with Budd-Chiari syndrome underwent liver transplant and subsequent splenectomy. Her platelet count began to rise postoperatively after previous normal values. JAK2V617F-positive essential thrombocythemia (ET) was diagnosed.