Figure 2: Histopathological examination of granulocytic sarcoma (GS) in the presented case. Histopathological examination (hematoxylin and eosin (H and E) staining) showed that the tumor is composed of uniform population of malignant round cells with a high nuclear-cytoplasmic ratio, irregular nuclei, and prominent nucleoli (a). Immunohistochemically, most tumor cells were positive for myeloperoxidase (MPO) (b), negative for CD3 (c) and CD20 (d). Original magnification: x200