[Introduction and history of surgery of the third ventricle]

In this annual report of the Société de Neurochirurgie de Langue Française, the authors reviewed in a retrospective study 262 cases of tumors exclusively located in the third ventricle (thalamic, chiasmatic and pineal tumors were excluded). Modern neuroradiology easily discloses these lesions, and therapeutic management represents the main challenge : most of the patients present with few symptoms, and even in some cases the lesions are diagnosed fortuitously. Neuropsychological assessment appears necessary to evaluate the long-term outcome of the patients : unfortunately few cases in this series were informative for these data. Walter Dandy described the operative approach of these tumors in 1922, and he also reported the benefits of endoscopy. Almost 80 years later, technical advances such as CSF shunts, stereotaxis, neuronavigation have improved the results of the neurosurgical treatment of these deep-seated lesions.