[Diagnostic and therapeutic management of essential thrombocythemia in children].

Background: Essential thrombocythemia is a myeloproliferative disease resulting from the clonal proliferation of a multipotent myeloid stem cell with an increased platelet count in peripheral blood. In 2% of cases the cause remains unknown. It is then called idiopathic essential thrombocythemia.

The Aim: The objective of this study was to present the diagnostic and therapeutic management of essential thrombocythemia in children.

Material And Methods: The authors analysed complete medical records of 5 patients treated for essential thrombocythemia in the Department of Children Haematology and Oncology, Medical University Lublin during a 6 years (1996-2002) period. The investigated group consisted of 5 children: 3 boys and 2 girls with mean age of 7 years and 8 months (varying from 5 years and 3 months to 11 years and 8 months).

Results: The peripheral platelet count was above 1200 x 10(9)/L. Three patients developed functional symptoms of microvascular blood flow alteration (headaches, sensory disorders. paresthesiae). In 2 patients thrombocythemia was asymptomatic and the diagnosis was made incidentally. Diagnosis of essential thrombocythemia was made according to the criteria of the Polycythemia Vera Study Group and treatment with anagrelide hydrochloride was started. One patient due to bad drug tolerance was treated with hydroxyurea. Treatment of essential thrombocythemia in all patients resulted in: (1) decreased (500-600 x 10(9)/L) platelet count in peripheral blood; (2) resolving the symptoms of small vessels obturation (headaches, sensory disorders, paresthesiae); (3) low platelet separating megakaryocytes count in control myelograms (4) no transformation into acute neoplastic disease.

Conclusions: In the treatment of children with essential thrombocythemia anagrelid was effective in four of five patients.