[Extraneural metastasis of central nervous system tumours (author's transl)].

Extraneural metastases of central nervous system tumours are very rare (248 of histologically proven examples in the literature). They are mainly in adult males and in the following descending order of frequency: gliomas (39.5%), meningeal tumours and sarcomas (28.2%), neuronal tumours (14.1%), lymphomas-microgliomas (12.5%), pineal tumours (4%) and melanomas (1.6%); 10 cases out of 248 developed through a shunt. 19 were observed without any surgical operation. There are still many uncertainties about their pathogenesis. It seems however that in some tumours the increased survival time and the repetition of the craniotomy favorises the metastasis.