Fig. 1

a Diffuse infiltrate of large atypical lymphocytes and a few erythrophagocytes (arrow) in bone marrow (patient No. 4). b Bone marrow invasion by atypical medium-sized and some large atypical lymphocytes with hyperchromatic nuclei in patient No. 12. Histiocytic reaction and a few erythrophagocytes were detected. An erythrophagocyte and atypical lymphocyte in a smear. c Lymph node involvement of large atypical lymphocytes and some erythrophagocytes in patient No. 5. d Diffuse infiltrates of large atypical lymphocytes in the hepatic lobules (patient No. 11). Destructed hepatic trabeculae are observable in the right upper part, and a few erythrophagocytes are seen. e Diffuse infiltrate of large atypical lymphocytes and many apoptotic bodies in involved subcutaneous tissue of patient No. 13. f Diffuse infiltrate of small lymphocytes with mild atypia and several scattered erythrophagocytes in lymph node of patient No. 16. × 400