Idiopathic Myelofibrosis Followed by Acute Lymphoblastic Leukemia

Idiopathic myelofibrosis is a rare disease in childhood. Twenty-one cases were found in a literature search through 1979. 1-5 Fifteen of these were diagnosed in the first three years of life, and more than 50% of the patients had died within one year of diagnosis. In adults, idiopathic myelofibrosis is considered a type of myeloproliferative disorder, and myelogenous leukemia develops in as many as 20% of such patients. However, in children, acute myelogenous leukemia developed in only one of the above-mentioned 21 cases. 2 The following case is presented to emphasize that leukemia can subsequently develop in children with myelofibrosis and to point out that not only myelogenous, but also lymphoblastic leukemia may ensue. Report of a Case .—An infant boy was hospitalized at the age of 5 months for evaluation of anemia and thrombocytopenia. Medical history and family history were unremarkable. Physical examination revealed petechiae of the arms and