FDG PET/CT in Pediatric Neurolymphomatosis.

An 8-year-old girl presented with back and leg pain and left arm and leg paresis. Lumbar puncture was suggestive of lymphocytic meningitis without identified organism. A second lumbar puncture demonstrated a large number of lymphoid B cells, with positive immunohistochemical staining for CD20 and CD25, proving the diagnosis of neurolymphomatosis. Brain and spine MRI demonstrated involvement of cervical and lumbosacral nerve roots. FDG PET/CT showed multiple bone metastases in addition to nerve involvement. Postchemotherapy FDG PET/CT demonstrated complete metabolic response.