[Tumors of the third ventricle: review of the literature].

In this chapter, the authors compared the results of the national series (262 patients) with the relevant data from the literature, in order to establish the optimal therapeutic management. Colloid cysts represent the main tumor encountered within the third ventricle (145 cases). Sudden death from colloid cysts is documented in this series, but neurosurgeons should also be aware of the increasing number of fortuitous diagnosis of such lesions. The liquid consistency of the content of the cyst is the major argument to choose the surgical procedure. Liquid colloid cysts usually associate isodense appearance on CT Scan, hypo-intensity on T1 weighted MRI images, and hyperintensity on T2-weighted MRI images. Endoscopy now appears as an accurate surgical procedure. A surgical strategy is proposed. Among glial tumors, pilocytic astrocytomas are poorly documented in the literature. Low grade astrocytomas, ependymomas, subependymomas and giant cell subependymal astrocytomas, gangliogliomas, and oligodendrogliomas were reviewed with the relevant literature. Other tumors are rare in the third ventricle, except for choroid plexus papilloma and craniopharyngioma. The reality of purely intraventricular craniopharyngioma is confirmed by the experience of this series. Other lesions such as meningioma, cavernoma, germ-cell tumors, lymphomas, metastasis, epidermoid cysts, and exceptionnal lesions were also reviewed.