Acute megakaryocytic leukemia (AMKL) with major myelofibrosis in an infant. Diagnosis by liver biopsy and response to treatment.

An infant presented with enlarged liver and spleen and profound pancytopenia. Severe marrow fibrosis impeded the diagnosis which was achieved by liver biopsy: Fibrosis surrounded foci of blasts which were shown by immunologic markers to originate from the megakaryocytic lineage. Complete sustained remission was obtained by low-dose aracytine therapy. The child was disease-free at 40 months' follow up.