Dural invasion by pituitary tumours.

In 12 cases of pituitary tumour the dura mater of the sella turcica or diaphragma sellae in contact with the tumour was examined histologically. In nine cases tumour cells were found lying deep in the substance of the dura. Dura from the sella of seven subjects without pituitary disease, obtianed at autopsy, showed no inclusions of pituitary tissue. Four of the cases studied were known before death to suffer from an invasive pituitary adenoma. Of eight surviving cases operated upon in the last two years, five showed dural invasion by tumour. The present report suggests that the condition may be more frequent than expected and that with more study it may provide an index of prognosis. It also defines a requirement for the surgeon aiming to prevent recurrence of tumour after operation or to achieve a complete endocrine ablation.