Two patterns of tumor invasion identified in the diagnostic PCNSL specimen (subtotal resection) from the patient in Figure 2. Hematoxylin and eosin (×10). (A) In a background of necrosis (blue arrows), and hemorrhage (black arrow) angiotropic growth of viable DLBCL (white arrows), in which lymphoma cells appear to coopt brain vasculature. (B) In a separate area containing predominantly normal brain elements, angiotropic lymphoma cells (white arrow) are noted within the perivascular (Virchow-Robin) space. (C) A second pattern is direct invasion, for example, into the meninges (white arrows).