The authors report a case of neuronal ceroid lipofuscinosis (Kufs' disease) 
confirmed by stereotactically obtained brain biopsy findings and initially 
diagnosed as a butterfly glioma. The presenting symptoms in the 64-year-old 
patient were mental alterations with progressive dementia, followed by muscular 
atrophy and myoclonia with distal preponderance. The mild initial disturbances 
of coordination increased, and the patient developed a markedly ataxic gait. 
Computerized tomography (CT) scanning and magnetic resonance imaging revealed 
generalized cerebral atrophy and a bifrontal space-occupying lesion involving 
the callosum. The original "clearcut" diagnosis of glioblastoma multiforme, 
based on CT scans, was unexpectedly disproved by examination of stereotactically 
obtained brain biopsy specimens, which revealed a neuronal ceroid lipofuscinosis 
(Kufs' disease). To the authors' knowledge, this is the first report of a case 
presenting with both diffuse brain atrophy and localized accumulation of 
neuronal lipofuscin, mimicking a mass lesion on radiological studies.