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. This case demonstrates that the diagnosis of ET should be considered in the face of normal platelet counts and included on the differential diagnosis for pediatric patients. With this population in mind, we review the current literature on long-term use of platelet-lowering agents. We conclude that it is reasonable to use anagrelide as a first-line treatment for ET diagnosed according to the World Health Organization (WHO) system. In cases where WHO criteria do not result in a definitive diagnosis or when a patient experiences thrombotic events despite anagrelide therapy, hydroxyurea may be utilized as a first-line agent or as an adjunct. Further study in this area is warranted.