They are commonly gray-pink with a homogeneous circumscribed mass that is firmer than the surrounding brain. There may be necrosis or hemorrhage but cystic change is rare. They may be surrounded by considerable edema. This is a highly cellular tumor with necrosis. An astrocytic reaction may be present.
Endothelial proliferation is usually absent.
The basement membranes may be multiplied. Hodgkin's is very rare . Four Main Histological Features of PCL 1. Affinity of the neoplastic cells for blood vessels and their surroundings. There is diffuse infiltration of the parenchyma for some distance beyond the grossly evident tumor.