Case Report: Chronic myeloid leukemia in a 13-year-old—a rare pediatric case of extreme hyperleukocytosis in chronic phase

Pediatric Chronic Myeloid Leukemia (CML), a rare hematologic malignancy, accounts for only 2–3% of cases of leukemia in pediatric patients. The case presented here is of a previously healthy 13-year-old male, who came to the emergency department with increasing fatigue, abdominal distention, and discomfort. On examination, he was pale with significant splenomegaly. His investigation findings included marked leukocytosis (WBC > 600 × 10 9 /L), severe anemia (Hb 5 g/dL), along with thrombocytosis (Platelets > 1,530 × 10 9 /L). The diagnosis was made by peripheral smear and bone marrow biopsy, showing Chronic Phase CML with less than 3% blasts along with intense granulocytic hyperplasia. Molecular studies by PCR identified the BCR:ABL1 fusion transcript. The initial treatment approach emphasized cytoreduction therapy with hydroxyurea, intravenous fluid administration, and preventive medication with allopurinol to protect against the risk of tumor lysis syndrome. After the patient became stabilized, imatinib, a first-line tyrosine kinase inhibitor, was started. The supportive care consisted of transfusion support and gastrointestinal protection. The patient responded quite well to therapy and was therefore discharged with instructions for further follow-up care. As highlighted by this case, the importance of prompt diagnosis, the initiation of cytoreduction therapy, and the use of molecular therapy in treating CML in children cannot be neglected. CML in children is an uncommon but curable form of leukemia.