[Colloid cysts of the 3d ventricle: problems of early intravital diagnosis]

Basing on two own cases with acute signs of increased obstructive intracranial pressure the problem of early diagnosis of colloid cysts of the third ventricle is discussed with special reference to case reports in the literature. In the absence of typical clinical signs and symptoms, there are acute and chronic constellations of signs and symptoms that point to a suspicion of an obstruction of liquor flow by a colloid cyst. It is explained which importance CT and MR assume in the diagnosis of these benign tumours that present a very varied neurological pattern. Special reference is made to the presentation of neuroradiological differential diagnoses and the application of specific examination methods, such as tomography in very thin layers and allowing some time to elapse after contrast medium administration has been effected.