Pediatric acute lymphoblastic leukemia and leukapheresis: CT evidence of hemorrhagic complication.

Leukapheresis has been used widely to quickly reduce white blood cell count (WBC) in patients with hyperleukocytosis. Despite its wide utilization, leukapheresis has risks of complication, which have not been thoroughly reported in pediatric patients. No report was found in English literatures about leukapheresis complications in children with acute lymphoblastic leukemia (ALL). We reported a 4-year-old girl with ALL and hyperleukocytosis, with no sign of bleeding. After leukapheresis, WBC and platelet count decreased, and patient complained of headache. Neurological deficit developed quickly afterwards. Intracranial infection was suspected clinically. Contrast-enhanced head CT revealed multiple hyperdense lesions and diffuse cerebral oedema. The patient was subsequently diagnosed with multiple intraparenchymal hemorrhage, and leukapheresis was stopped. Intracranial hyperdense lesion in leukemic patients has many differential diagnosis, such as infection, granulocytic sarcoma (chloroma), and hemorrhage. Lesion characteristics in CT could help point the diagnosis. History of leukapheresis should also raise suspicion of hemorrhage. This article discussed CT characteristics of multiple brain hemorrhage in pediatric ALL after leukapheresis and how to differentiate it with other common intracranial complications of leukemia.