[Computer tomography in tumors of the posterior portions of the 3d ventricle and pineal body].

Computer tomography was applied in the examination of 72 patients with tumors in the posterior parts of the third ventricle and pineal body. Direct and indirect signs of tumors of this region were established. The direct signs are a zone of increased density in the region of the posterior parts of the third ventricle and the pineal body and total or partial tamponade of the lamina tecti cistern. Hydrocephalus of the ventricles and anterior parts of the third ventricle is an indirect sign. In 18 patients the CT pattern of the tumor was compared with its histological picture. It was found that a large homogeneous zone of rather high density with one or more petrifactions in the tumor tissue was more characteristic of malignant tumors (germinoma, pinealoma, anaplastic ependymoma). A small zone of nonhomogeneous relatively increased density with less frequently encountered calcifications was more typical of benign tumors (teratoma, pinealoma, ependymoma) of this region. The diagnosis of germinoma of the pineal body can often be made from the CT picture, in which case a very characteristic sign of "auricles" is demonstrated; it is caused by metastatic spread of the tumor to the subependymal layer of the anterior horns of the lateral ventricles. The role of CT in appraising the results of radiotherapy in tumors of the pineal body is shown.