1898 Journal of the American Medical Association (JAMA)  
ylin the cells immediately about the blood vessels are more deeply stained than those lying at points remote. This gives to the tumor almost the appearance of angioma. This condition is to be accounted for in a large measure by the high intraocular tension, which has the effect of squeezing out the life of the cells remote from the blood vessels, and consequently these cells appear in the sections necrotic, while those surrounding the vessel retain their vitality and stain deeply. Recent work
more » ... eply. Recent work has shown that the tumor does not originate, as was once thought, from the external or from the internal granular layers. It will be remembered that the cells in a glioma morphologically resemble those in the granular layers of the retina, and this seemed a strong reason for supposing that here the tumor originated. Improved methods of staining, however, have shown that the tumor cells are not only like those in the granular layers, but that they are of different sizes and shapes, some being oval and some having processes and resembling a rosette. The theory as to the origin of these tumors is new. It is not an uncommon thing to find in a normal retina cells which are out of place, that is to say, cells in one layer which morphologically belong to another layer, as, for instance, ganglion cells in the internal granular layer, and vice versa. These cells have been called by Cajal, Wintersteiner, Greef and others, misplaced cells, and these observers have noted that gliomata are made up largely of these misplaced cells. The conclusion is then that a glioma orignates from a cell which is misplaced in fetal life, and which misplacement may occur in any one of the retinal layers. Dr. Thompson-In closing I would like to say that those cases which have returned have done so inside of seven months.
doi:10.1001/jama.1898.92450120006002a fatcat:danecnsqvbfazi2u727zgn3diq