Childhood leukemia: central nervous system abnormalities during and after treatment.

PURPOSE To document the radiologic abnormalities seen in the central nervous system (CNS) during and after treatment of childhood leukemia. METHODS MR images (19 patients) and CT scans (12 patients) were reviewed retrospectively in 19 children and adolescents with neurologic complications of leukemia or its treatment. Patients were divided into two groups: the first included those with disease-related complications of leukemia, such as meningeal and parenchymal leukemia, chloroma, and cerebrovascular disorders; the second included patients with treatment-related neurotoxicity and infection caused by immunocompromised states. Pathologic confirmation of the CNS lesions was obtained in eight patients. Factors that predisposed to the development of tumor-related or treatment-related complications were determined by reviewing the medical records. RESULTS Among the 19 patients, 10 had two or more different CNS abnormalities found on CT scans or MR images. The imaging abnormalities seen in 12 patients during treatment included sinus thrombosis (n = 3), transient gray or white matter ischemia (n = 2), presumed disseminated microinfarcts (n = 1), cerebral hemorrhage or infarct (n = 3), inflammatory demyelinating polyradiculoneuropathy (n = 1), infections (n = 4, 2 bacterial and 2 fungal), and meningeal leukemia (n = 2). After therapy, seven patients had CNS imaging abnormalities, including secondary brain tumors (2 malignant gliomas and 1 CNS lymphoma), spinal chloroma (n = 1), necrotizing leukoencephalopathy and mineralizing microangiopathy (n = 3), cerebral mucormycosis (n = 1), spontaneous intracranial hemorrhage (n = 3), and spinal meningeal leukemia (n = 1). CONCLUSION The wide spectrum of CNS abnormalities that occur during and after treatment for leukemia is related to the inherent risk of the leukemia itself, to the treatment method, and to the duration of survival. Because many neurologic complications of leukemia are treatable, early diagnosis is essential.