Myelofibrosis in a child suffering from a hypereosinophilic syndrome with trisomy 8: response to corticotherapy.

The idiopathic hypereosinophilic syndrome (IHS) is extremely rare in childhood and relationships of this syndrome with myeloproliferative diseases are controversial. We reported the observation of a 7-year-old girl suffering from an IHS with myelofibrosis. A clonal cytogenetic abnormality, trisomy 8, was detected in the bone marrow cells of this child. This is the decisive proof of a myeloproliferative disorder. IHS with myelofibrosis is usually considered as unresponsive to corticotherapy. In our case, corticotherapy resulted in a rapid, complete, and lasting disappearance of myelofibrosis. Complete remission of the disease, however, was not achieved and the trisomy 8 persisted after treatment.