Ultrastructure of Capillary Reaction to Brain Tumors

Abstract

The study of changes in the structure of blood vessels within and adjacent to intracranial neoplasms is important because these alterations may not only signify the pathological reaction to neoplasia, but may give some indication of vessel function in the normal state as well. Endothelial proliferation is the best-known physiological response to this pathological lesion. Most neoplasms, with the possible exception of vascular tumors, derive their blood supply from adjacent tissue parenchyma. Usually the blood vessels supplying such new growth proliferate at a rate proportional to the growth rate of the neoplasm. Morphological evidence of rapid capillary growth has been accepted as one criterion of malignancy of intracranial tumors. In addition to endothelial proliferation, vascular malformations have been described, especially in glioblastoma multiforme. Arteriovenous shunts, angiomatous conglomerates, and aneurysmal dilatations have recently been extensively described by Nystrom.¹ The functional changes of these intracerebral vessels are more complex and less