Acute promyelocytic leukemia in children

Sixteen children (ages 2--17) with acute promyelocytic leukemia (APL) were studied retrospectively. Diagnosis was based on clinical features and morphological criteria of the FAB classification. Bleeding diathesis was the predominant presenting symptom (greater than 85%), associated with laboratory findings of disseminated intravascular coagulation (DIC). Extramedullary manifestations included skin rash in six patients, gum infiltration in two, and meningeal leukemia in two. Induction therapy consisted of cytosine arabinoside and an anthracycline, with or without other agents. Prophylactic heparinization was given to 12 patients. Six patients (37.5%) failed to achieve remission and died, secondary to hemorrhage in three, and secondary to infection in the remaining three patients. The median duration of remission was 14 months, and the median survival for responders was 21 months. One meningeal leukemia preceded bone marrow relapse despite intermittent intrathecal chemotherapy for prophylaxis. Three patients remain in continuous complete remission 3 years after initial diagnosis. Although childhood APL shares many features of its adult counterpart, the high frequency of extramedullary manifestations and mortality secondary to neutropenia deserves separate attention.