Figure 2A-F.
2A . Histologic sections show central nervous system tissue with an extensive, polymorphous lymphoid infiltrate (blue arrows ) showing numerous areas of angioinvasion and destruction (black arrows), and a focal area of necrosis (red arrow ) (hematoxylin and eosin, 4x ). 2B . Higher power shows area of central necrosis (red arrow ) surrounded by atypical lymphocytes (blue arrow ) admixed with numerous histiocytes (green arrow ) (hematoxylin and eosin, 20x ). 2C.High power shows numerous medium to large-sized atypical lymphocytes (hematoxylin and eosin, 40x ). 2D. Immunohistochemistry shows that the majority of lymphocytes are mature T-cells (CD3, 20x ). 2E . Immunohistochemistry highlights scattered large atypical B-cells with focal involvement of vessels (CD20, 40x ).2F. In-situ hybridization for EBV-encoded small RNA (EBER) is positive in rare large atypical lymphocytes (EBER, 20x ).