Megakaryoblastic transformation of chronic myelogenous leukaemia in a child

A child with megakaryoblastic transformation of Ph1-positive chronic myelogenous leukaemia, complicated by myelofibrosis, is reported. The blastic cells were negative for myeloperoxidase by ultrastructural cytochemistry. They had Factor-VIII antigen and platelet glycoprotein but were negative for platelet peroxidase activity. This discrepancy seemed to be due to neoplastic origin of blastic cells.