Colloid Tumors of the Third Ventricle

Colloid cysts of the third ventricle, represented by twenty-eight reports in the literature, are among the less frequently encountered tumors of this region. Their position in the ventricular system, which permits them at times to block either or both foramina of Monro or the aqueduct of Sylvius, and their relation to the closely adjacent hypothalamic nuclei often give rise to a fulminating clinical picture. Sudden death is a frequent occurrence in tumors of this kind. Those cysts which interfere only intermittently with the circulation of the ventricular fluid and those which elicit but few symptoms referable to the vegetative centers offer difficult diagnostic problems. Recently we had the opportunity to study two patients with this type of tumor whose cases presented some difficulties in diagnosis. It is our purpose to describe these cases in detail and to discuss the diagnostic and anatomic problems presented by colloid tumors of the third