[Optic chiasm gliomas (author's transl)].

A follow up study of 40 cases of optic chiasm gliomas is presented. Histological examination was obtained in 26 cases. All were bipolar spongioblastomas. Four of these were optic nerve gliomas, 17 chiasmatic gliomas and 19 invasive optohypothalamic tumors. The main clinical features are reviewed with special attention to endocrine disorders, including precocious puberty and diencephalic emaciation. Neurofibromatosis was present in 30%. Diagnostic difficulties are outlined, especially in chiasmatic tumors without optic nerve involvement: event with C T scan, the differential diagnosis with ectopic pinealomas, craniopharyngiomas and primary hypothalamic tumors, may be difficult. The operative mortality was 12% (3/25). All but one, had radiotherapy either alone or post operative. All four of the patients with unilateral optic nerve gliomas have a normal C T scan more than 10 years after treatment. Of the 17 patients with chiasmatic gliomas, 14 are alive with normal C T scan in 2 cases, and with reduction in size of the tumor in 7. Eleven of 19 patients with invasive gliomas are alive with diminished size of the tumor in 7. Improvement in visual acuity, reduction in size of tumor mass, persistent increase in size of non irradiated tumor and lack of recurrence of optic nerve glioma even with histological proven chiasmatic involvement is taken as evidence of the effect of radiotherapy. The sub frontal approach is emphasized for optic nerve and optic chiasm tumors: it provides direct surgical verification with the opportunity for complete removal, large biopsy, decompression of the optic foramina or cyst removal. Regarding secondary endocrine disorders, radiotherapy is discussed in children. If necessary it must be managed under careful evaluation of endocrine status, principally growth function.