The 70-year-old female patient presented with slowly worsening gait disorders, nausea and intermittent piercing bifrontal headaches. Shortly before admission, an acute deterioration was experienced with acute psychosyndrome, dysarthria and paresis of the left arm. The imaging diagnostics showed a unilateral expansion of the right lateral ventricle caused by an enhancing lesion in the area of the right foramen of Monro. A second enhancing lesion could be see in front of the right anterior horn.