[en] Gliomatosis cerebri is a rare infiltrating neoplasm of the glial cells that presents with diffuse involvement in then brain. The progressive and diffuse nature of this lesion, together with the highly variable clinical signs, make its clinical diagnosis difficult. There are no typical findings in computed tomography images. The extension of the tumor is much more reliably determined by magnetic resonance. The diagnosis is suspected in the presence of a diffuse brain lesion with no mass or necrosis producing the overgrowth of cerebral structures and with the tendency to involve the midline connection pathways. We present a case of gliomatosis cerebri in which the magnetic resonance images led to the suspected diagnosis. (Author) 16 refs