[The microsurgical treatment of the so-called tuberculum-sellae-meningiomas (author's transl)].

Experience from five cases operated on within one year (among 50 microsurgical operations at the base of the brain) persuades us to discuss the topical relations of the meningiomas of the tuberculum sellae and the modifications in operating techniques necessary. For the two contrasting types of tumour found, which are:-- 1. Tumours en plaque with osseous reactions, particularly of the sphenoidal ridge, in which the exact predetermination of the positions of the optic nerve and of the carotid artery is facilitated by means of measurement and by fronto-temporal approach (which does not preclude a frontal or a bifrontal approach). 2. Suprasellar tumours whose topical relationships to the posterior surface of the chiasma, the pituitary stalk, the big vessels, and the perforating arteries increase the risk of operation. Radical operations for tumours near the pituitary stalk are not always advisable. Pre- and postoperative analysis of the anatomical characteristics of the individual case is essential before microsurgical intervention.