The case of a three-years-old male with intracranial hypertension is reported. Without a clear clinical diagnosis, a gradual deterioration ocurred before his death, 8 days later. The neuropathological examination of the brain revealed a tumor with indistint borders at the right lateral ventricle, with granulous surface, pink-gray colour, irregular necrotic and hemorragic areas, invading the adjacent brain tissue. The histopathological study revealed a malignant variant of the choroid plexus tumor, of extreme rarity in the central nervous system. The biological and histological criteria accepted by Lewis, Rubinstein and Polak for the correct diagnosis of this type of tumour are discussed.