Pediatric patients with essential thrombocythemia (ET) typically present with low-risk disease, though those with clonal ET have clinical features similar to adults with ET, according to a review published in Expert Review of Hematology. This review noted that children with prolonged, nonsecondary thrombocytosis may actually have ET even though ET is exceptionally rare in the pediatric population.
In diagnosing ET in children, clinicians must rule out secondary thrombocytosis in children with sustained platelet counts over 450 x 109/L. An ET workup should account for possible mutations in CALR, MPL, and JAK2V617F that are drivers of myeloproliferative neoplasms, though the majority of children with ET have triple-negative disease for these mutations.
Clinicians can adopt an approach of surveillance for asymptomatic pediatric patients with ET, and children with clonal ET can be considered low-risk patients as they infrequently experience thrombotic or hemorrhagic events. Though thrombotic and hemorrhagic events are less frequent in children with ET than in adults, these events represent a more serious burden in pediatric patients when they do occur.
Because most pediatric patients with ET do not have JAK2 mutations or a previous history of thrombotic events, they are considered low-risk. However, as in adults, the presence of JAK2 mutations confers an increased risk for thrombotic events.
Though there are no defined guidelines for treating pediatric ET, a variety of therapeutic options are available. Aspirin can be used to treat headaches and microvascular disturbances. Anticoagulants should be used in patients with venous thrombosis.
Cytoreductive agents should only be used as a last choice and only in patients with intermediate to high risk. Hydroxyurea and interferon alfa are both frontline choices for any age. Long-term use of hydroxyurea, however, might be mutagenic.
The authors encouraged the development of collaborative studies that could accrue sufficient evaluable cases to better elucidate risk stratification and therapeutic management.
1. Randi ML, Bertozzi I, Putti MC. Contemporary management of essential thrombocythemia in children [published online April 27, 2019]. Expert Rev Hematol. doi:10.1080/17474086.2019.1602034