The case of a six-year old boy's with intracranial hypertension and cranial deformities is reported. Radiological examination showed signs of intracranial hypertension and a large osteolitic area in the left posterior parietal region. Cerebral cintilography showed many abnormal captation areas. Pneumoencephalography showed deformation of the ventricular system without dilatation. Angiographic study gave images of tumoral compression by meningite processes. Craniotomy in the osteolytic area showed an infiltrating tumoration between dura and piamater, reaching frontal, temporal and bilateral parietal areas. Histopathological examination confirmed the diagnostic of fibromixosarcoma.