Fig. 3.

The examination of bone marrow revealed evident histiocytes with hemophagocytic activity (Hematoxylin and eosin stain; original magnification, 40 $\times$) (a), as were increased numbers of CD8⁺ T cells with modest cytological atypia (b). CD20.⁺ B cells (c) and positive Epstein–Barr virus–encoded RNA in situ hybridization were rare (d). (Hematoxylin and eosin stain, immunohistochemistry stain; original magnification, 20 $\times$)