[Computed tomography in leptomeningeal and ventricular spread of primary brain tumors (author's transl)]

Of 8000 consecutive patients studied with computed tomography, 10 patients with primary intracranial tumors (germinoma, medulloblastoma, malignant teratoma and glioblastoma) showed ventricular or leptomeningeal spread of the tumor cells. In patients with leptomeningeal spread, computed tomography showed obliteration of basal cisterns and sulci with isodense or slightly hyperdense mass, which was markedly enhanced following administration of the contrast medium. In cases of ventricular spread, a narrow zone of high density was noted on the ependymal surface, and it was also markedly enhanced with the contrast medium. Similar CT scan appearance of contrast enhancement in the subarachnoid space or in the ventricular surface was, however, noted also in the infectious processes such as basal arachnoiditis or ependymitis, and the differentiation of the neoplastic process from the infectious lesions seemed impossible based on the CT scan appearance alone.