[Chronic-phase chronic myeloid leukemia with intracranial hemorrhage complicated with tumor lysis syndrome].

A 14-year-old male with autism was admitted to our hospital owing to altered consciousness and gait disturbance. Blood tests showed a white blood cell (WBC) count of 728,600/µl, and brain computed tomography revealed intracranial hemorrhage and a midline shift of the brain. The chronic phase of chronic myeloid leukemia (CML) was confirmed as per bone marrow aspiration findings. The patient underwent emergency craniotomy for hematoma removal, and he subsequently received hydroxyurea and rasburicase combination therapy. However, he developed tumor lysis syndrome (TLS) and died on the second day of hospitalization. Histopathological examination of autopsy specimens did not reveal any condition that could account for his death other than CML. Several reports have described intracranial hemorrhage during the accelerated phase or blast crisis of CML, but few have described this complication during the chronic phase. TLS concomitant with CML in the chronic phase or following hydroxyurea (an inhibitor of DNA synthesis) administration is rare. It is essential for clinicians to be aware that patients with chronic phase CML and high WBC counts may develop TLS, following the administration of hydroxyurea alone. In addition, extreme caution is warranted in severe cases accompanied by intracranial hemorrhage.