Chronic myeloid leukaemia with pulmonary leucostasis in a young Down syndrome patient

We reported a rare case of chronic myeloid leukaemia (CML) complicated with pulmonary leucostasis in an 11-year-old Down syndrome (DS) patient who presented with respiratory distress. His peripheral blood investigation showed features of CML with 17% circulating blast, with immunophenotyping showing positivity towards myeloid markers. Peripheral blood polymerase chain reaction for BCR–ABL fusion transcripts was positive, and cytogenetic studies showed Ph chromosome with trisomy 21. Despite cytoreduction therapy with hydroxyurea and leukapheresis, the patient succumbed due to shock, with multiple organ failure. Our case highlights the need for early detection and rapid referral for aggressive treatment in DS patients with CML, as the combination is associated with a poor outcome.