Optic nerve gliomas. I. Clinical diagnosis and pathology.

At the National Institute of Neurosurgery a team of ophthalmologists and neurosurgeons has for 20 years been collaborating in the research and treatment of optic nerve gliomas. Among 34 patients, 30 were under the age of 20 years, and 20 under the age of 10 years. Of the 20 patients younger than 10 years, 16 were girls. The clinical symptoms were classified into three groups: I. Unilateral visual impairment with unilateral axial proptosis (16 patients), strabismus (6 cases), and typical X-ray findings of the skull. II. Uni- or bilateral visual impairment without proptosis (12 patients), depressed vision in the homolateral eye (9 patients), hemianopia (2 out of 4 examined patients) and hemiparesis (6 cases). III. Uni- or bilateral visual impairment without proptosis but with hormonal or metabolic disturbances (6 patients). Carotid angiography and PEG were performed in groups II and III and revealed a picture that is characteristic of suprasellar tumours. 99mTc pertechnetate scanning was done in six cases and showed isotope accumulation in the tumour in five. Pathologically, considering also the clinical aspects, two types of localization merit consideration: 1. The relationship between the tumour and the optic nerve (tumours growing within and extending beyond the optic pathways, respectively) and 2. The site of the tumour within the optic nerve (intraorbital, intraorbital and intracranial, intracranial only, chiasmal, and diffuse). Our data of histology and tissue culture prove the benign nature of the tumour even in the recurrences.