Pediatric Chronic Myeloid Leukemia Presenting With Extreme Thrombocytosis Simulating Essential ThrombocythemiaBoklan, Jessica L., MD*; Walsh, Alexandra M., MD*; de la Maza, Michelina C., MD*; Su, Leon L., MD†; Nizzi, Francisco A. Jr, DO†; Schafernak, Kristian T., MD†Journal of Pediatric Hematology/Oncology: August 2018 - Volume 40 - Issue 6 - p 456–457 doi: 10.1097/MPH.0000000000001154 Morphology Corner Abstract Author Information A 10-year-old boy presented with spontaneous bruising and was found to have extreme thrombocytosis without neutrophilia/shift to immaturity, basophilia or eosinophilia. While the peripheral blood and bone marrow findings initially suggested essential thrombocythemia, BCR-ABL1 translocation was detected and chronic myeloid leukemia, chronic phase, was diagnosed. Apheresis for platelet depletion was performed as a bridge given the delayed effects of medical therapy. *Division of Hematology/Oncology, Phoenix Children’s Hospital †Department of Pathology and Laboratory Medicine, Phoenix Children’s Hospital, Phoenix, AZ The authors declare no conflict of interest. Reprints: Kristian T. Schafernak, MD, 1919 E Thomas Road, Phoenix, AZ 85016 (e-mail: email@example.com). Received November 9, 2017 Accepted December 17, 2017 Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.