[Differential diagnosis between third-ventricle neoplasms and tumors of the posterior fossa based on clinical manifestations and results of contrast radiograms of the brain].

Differential diagnosis in the material was based on the neurological and radiological findings made in 45 patients with third-ventricle tumours and 133 with subtentorial tumours. No clinical syndrome has been found which could help in reliable diagnosis concerning either of these locations of the tumour. Of decisive significance for the correct localization of tumours was ventriculography which established the diagnosis in 42 cases of third-ventricle tumours and 103 cases of subtentorial tumours. The most difficult problem was recognition of the relation of the subtentorial tumours to the brain stem since this relation could not be indicated unequivocally neither by clinical findings nor by radiological examination. This required surgical revision of the posterior fossa in most cases with suspected brain stem tumours.