Fig. 2.
EBV-positive diffuses large B cell lymphoma, NOS. A–D Polymorphic variant with numerous HRS-like cells. A Low magnification of a lymph node diffusely infiltrates with geographic areas of necrosis (original magnification, ×50). B EBER in situ hybridization shows diffuse EBV-positive tumor cells surrounding the necrosis (original magnification, ×100). C Polymorphous proliferation characterized by small lymphocytes, plasma cells, histiocytes, and scattered large transformed cells mimicking Hodgkin and Reed–Sternberg (HRS) cells. Insert: the HRS-like cells are LMP1 positive (original magnification, 400×). D The HRS-like cells are strongly CD20 positive. Note the polymorphic B cell infiltrate. E–F Monomorphic type of EBV-positive diffuses large B cell lymphoma, NOS. E The lymph node is diffusely replaced by a monomorphic infiltrate of large centroblastic cells. F EBER in situ hybridization is positive in almost 100% of the tumor cells. (E–F original magnification, ×400)