Figure 2.

Microscopic findings and immunohistochemical staining. A: Histological examinations stained with hematoxylin and eosin revealed diffuse round to oval medium sized cells with high nuclear/cytoplasmic ratio, finely dispersed chromatin, scanty cytoplasm, prominent nucleoli, and numerous mitoses, × 200. B: Immunohistochemical staining showed that tumor cells was positive for TdT, × 400; C: Immunohistochemical staining showed that tumor cells was positive for CD5, × 400. D: Immunohistochemical staining showed that tumor cells was positive for CD7, × 400.