Eosinophilia, chloromas and a chromosome abnormality in a patient with a myeloproliferative syndrome

The existence of eosinophilic leukemia remains controversial since many authors challenge the existence of this entity. We present a patient with a hypereosinophilic syndrome whose findings were consistent with a leukemic process. The patient's course was marked my signs and symptoms of myeloblastoma formation and his illness terminated in an acute blastic crisis. chromosome studies on peripheral blood leucocytes demonstrated aneuploidy and an abnormal number four chromosome with additional material on its long arm. This case appears to be an unusual example of a hypereosinophilic syndrome with both myeloblastoma formation and an abnormal leucocyte karyotype.