Primary cerebral melanomas. Report of six cases and a review of the literature.

Six cases of primary malignant melanoma of the leptomeninges and brain are reported. Three were diagnosed histologically at surgery, three at autopsy. Four presented as solitary brain tumours which is unusual compared to other reported cases. In all six there was infiltration of the leptomeninges which must be regarded as the site of origin. Three of the cases have had a relatively long survival, two of them have died 2 years after the operation, and the third patient is still alive 18 months after surgery. It is suggested that the frequency of these tumours is underestimated on account of their resemblance to astroblastomas and poorly differentiated astrocytomas, and because biopsies are not always taken from small and atypical haematomas.