Fig. 4

(a) Tumor cells were diffusely distributed, medium size, uniform in volume, with little cytoplasm, deep-stained nuclei, and homogeneous nuclear chromatin; immunohistochemistry; (b) Tumor cells were approximately 80% positive for c-myc (brownish granules); (c) Tumor cells were actively proliferating with > 90% positive for Ki-67(brownish granules); (d) Tumor cells were diffusely positive for the B-cell marker CD20(brownish granules)