HISTOPATHOLOGY OF CNS RADIATION 



183 



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Fig. 11. Area of necrosis in the spinal cord with connccti\e tissue proliferation and 

 coni]30i.uid granular corpuscle formation. l)ut without astrocytosis. Gallocyanin-\an 

 Gieson X 2'_'5. Same monkey as Fi-^. 7. 



insertion because of tlie possible participation of meningeal collagenous 

 tissue. However, in the depths of the lesions at a few weeks or months after 

 radiation, the same proliferation of collagenous tissue without admixture ol 

 astrocytes is present (Fig. 12). Occasionally, it can be seen that collagenous 

 tissue is growing into regions of fibrin deposition (Fig. 12). but usually such 

 a relationship cannot be established. When astrocytic proliferation is re- 

 sumed, these areas of collagenous scar remain lor the most part intact. 



An attempt has been made to hnd out whether there is secondary degen- 

 eration of the collagen and regrowth of new collagen, as has been described 

 in radiation reactions in the skin (Wolbach, 1909). Occasionally, hyalinized 

 collagen fibers into which secondary proliferation of collagenous tissue has 

 taken place, can be seen, but this is uncommon. Some vessel walls (Fig. 4) 

 have appearances suggestive of repeated collagenous repair. 



