Gliomas presenting outside the central nervous system.

Tumours outside the central nervous system rarely prove to be intracranial glioma metastases. The mechanism of glioma metastasis has been thought to be related to dissemination of tumour cells either at the time of surgery or later through the surgical defect. However, 8 cases have been recorded to date in which metastases have occurred in the absence of surgery. This report details the clinical findings in 2 such patients. One presented with a pharyngeal mass that was found to be a metastasis from an anatomically remote parietal lobe astrocytoma. The other patient presented with a C8 nerve root tumour which was external to the dura. Biopsy revealed an astrocytoma that had metastasized from the roof of the lateral ventricle. Possible mechanisms of pathogenesis are discussed, including that of neural spread.