Fig. 2

Histological features. Hematoxylin and eosin (H&E) indicated a cross distribution of deeply and lightly stained lesions. The deeply stained zone was mainly composed of a large number of plasma cells and lymphocytes, and interspersed in a flake-like, lightly stained area like stripes. The giant pleomorphic tissue cells characterized by abundant cytoplasm, vacuoles, large nuclei, and irregular nucleus were distributed in the lightly stained area. In the cytoplasm of histiocytes, emperipolesis showed as some lymphocytes and a small number of plasma cells were phagocytized