(A) Classical Reed-Sternberg (RS) cell showing strong cytoplasmic CPP32 immunostaining. (B) Case showing a mononuclear variant of RS cell negative for CPP32 immunostaining. (C) Nodular sclerosis Hodgkin's disease showing positive CPP32 immunostaining of lacunar cells. (D) Negative staining lymphohistiocytic cell (arrow) in a case of nodular lymphocyte predominant Hodgkin's disease. (E) Strong CPP32-positive immunostaining of the germinal center of a secondary lymphoid follicle with negative staining of mantle zone cells. (F ) Plasma cells showing strong cytoplasmic positivity for CPP32 immunostaining.