Pathologic and clinical features of PMBCL compared with related diseases. (Top panel) Representative H&E and immunohistochemical stains. Positivity of CD20 and CD30 in PMBCL is characteristic, although not mandatory, for the diagnosis of PMBCL. The H&E stain of PMBCL shows typical sheets of medium-sized to large cells containing abundant pale cytoplasm in a background of fine sclerosis. Of note, CD20 staining in nodular sclerosis subtype of cHL is typically heterogeneous, and CD30 is usually absent in DLBCL. (Bottom panel) The typical clinical features of PMBCL are given and contrasted with related entities.