Immunoelectrophoresis in the diagnosis of neuroectodermal and mesodermal intracranial tumours, especially those of the posterior fossa.

Immunoelectrophoresis of extracts of 200 intracranial tumours against rabbit anti-glioblastoma serum gave positive results (= precipitation) in all cases of tumours of neuroectodermal origin such as glioblastoma, astrocytoma, oligodendroglioma, ependymoma, neurinoma, and spongioblastoma. No immunoelectrophoretic precipitation was seen for any of the tumours of mesenchymal origin, for instance meningioma and metastases of cancer. On the basis of these findings, immunoelectrophoresis is considered to be a reliable method for differentiation between tumour tissue of neuroectodermal and non-neuroectodermal origin. Among the 41 posterior fossa tumours some unusual observations were made. Cerebellar angioblastoma (Lindau tumour) showed an atypically located precipitation line, which for the present is interpreted as an immunological reaction to vascular wall tissue. Furthermore, among the group of so-called medulloblastomas, two subgroups were distinguished on the basis of three parameters. The first of these subgroups comprises tumours whose immunoelectrophoretic pattern resembles that of gliomas, which are histologically characterized by neuroectodermal structures and which occur in younger children (5--10 years). The tumours of the second subgroup, which do not show this neuroectodermal immunoelectrophoretic pattern, have a sarcomatous character histologically, and occur in patients aged between 10 and 50 years. The view that medulloblastoma comprises a number of different types of tumour seems to be confirmed by this finding.