A 7-year-old girl presented with progressive dementia. 99-mTechnetium pertechnetate brain imaging and flow, cerebral angiograms, and a pneumoencephalogram revealed a large, bilateral frontal lesion that crossed the corpus callosum. At surgery, the consistency of affected brain tissue was soft. The histologic diagnosis was Schilder disease. Postoperatively, prednisone therapy was initiated because of clinical evidence of increased intracranial pressure, including funduscopic change. Within 4 months, the prednisone was discontinued, and the child completed the school year at the top of her class. Three years later she continued to function as a superior student, without demonstrable clinical neurologic abnormality.