Fig. 2. Bone marrow biopsy (A, hematoxylin and eosin stain, ×400) and immunohistiochemical staining results for CD3, CD20 and CD68 (B–D, ×400, respectively). The bone marrow biopsy shows normocellular marrow with diffuse infiltration of CD20-positive neoplastic lymphoid cells (orange arrows) accompanied by an increase of CD68-positive histiocytes with occasional hemophagocytosis (yellow arrows), indicating the presence of B-cell lymphoma associated with hemophagocytic histiocytosis.