The brain surrounding malignant gliomas: an ultrastructural study.

Brain samples were taken in macroscopically oedematous zones during 21 operations for malignant glioma, and studied with the electron microscope. Oedema was found in 17 cases, mostly as serous extracellular fluid. Vascular changes in the oedema region are mostly as serous extracellular fluid. Vascular changes in the oedema region are mostly secondary to oedema: the origin of oedema fluid ought to be found in the tumour proper. Cellular reaction is slight; neuronal lesions may be ascribed mostly to a perturbation of axonal flow. Oedema round malignant gliomas and oedema round other malignant or benign tumours are morphologically distinct.