[en] We report four cases of trigeminal neuroma. One of the patients had von Recklinghausen's neurofibromatosis with plexiform neurofibromas of the branches of the trigeminal nerve. MRI provided more information than CT as regards the spread of tumor: extension to the mandibular and maxillary division of the trigeminal nerve was well demonstrated on sagittal and coronal sections. This examination yielded an accurate census of the intraocular plexiform neurofibromas and allowed a correct preoperative diagnosis to be obtained. With Gd-DOTA, better definition of the outline of the tumours and of cystic components was obtained. However, CT was better for demonstration of bone erosions. (orig.)