A spectrum of neuroradiological findings in children with haemophagocytic lymphohistiocytosis

Background Haemophagocytic lymphohistiocytosis (HLH) is a rare multisystem disorder. CNS involvement is a frequent and poor prognostic component. Better neuroradiological surveillance may be beneficial for patient management and outcome. Objective To describe various neuroradiological findings in nine patients with HLH with an emphasis on correlation with disease activity and treatment response. Materials and methods Between 1996 and 2007, nine children with HLH with CNS involvement were identified in a single centre. Neuroradiological findings from CT, MRI, and proton MR spectroscopy, and the clinical records of the nine children were retrospectively reviewed. The frequency, distribution, characteristics of abnormal neuroradiological findings and changes during follow-up were correlated with clinical findings. Results Initial abnormal findings included multiple nodular or ring-enhancing parenchymal lesions, a laminated pattern of nodular parenchymal lesions on T2-weighted images, leptomeningeal enhancement, confluent parenchymal lesions, mild ventriculomegaly, and diffuse brain oedema. On follow-up imaging studies, haemorrhagic transformation and atrophy were seen where brain parenchymal lesions had been previously. These abnormal neuroradiological findings showed good correlation with clinical findings. Proton MR spectroscopy also demonstrated typical changes of metabolites during the course of the disease. Conclusion A spectrum of neuroradiological findings in children with HLH is well matched with the clinical course of the disease and, therefore, a comprehensive analysis of the findings is useful to monitor disease activity and treatment responses.