[Primary thrombocythemia in childhood].

Primary thrombocythemia is a myeloproliferative disease characterized by a sustained and marked increase in platelet count. The platelet number rises in excess of 1000 X 10(9)/l. Adult patients present with recurrent hemorrhages, thrombotic episodes and microvascular disturbances. It is a relatively benign disease and rarely reported in children. We describe two patients with a thrombocythaemia. The first, a 13 1/2 year old boy, had no complaints. A thrombocythemia (2167 X 10(9)/l) and splenomegaly were found by chance. He was treated with melfalan. Acetylsalicilic acid and dipyridamol were added as anti-coagulants. The second patient, a 12 year old girl, was submitted to a splenectomy at the age of 10, because of a traumatic rupture. Sixteen months later she was admitted to our hospital with symptoms of thrombotic as well as bleeding tendency. Periferal microvascular disturbances and symptoms on the basis of impaired cerebro-vascular bloodflow were found. The number of platelets was 5083 X 10(9)/l. She was treated in the same way as the first patient. Symptoms disappeared as soon as the number of platelets decreased. In both patients periferal blood and bonemarrow examination as well as platelet function, measured by aggregation studies, were abnormal. Consideration of the literature on children and our own case I indicate that this disease in the younger patient may exist without undue risk of complications. One might consider treatment with anti-aggregating agents only.