Fig. 4.
Histologic and phenotypic features of BLL.
(A) Starry-sky pattern (hematoxylin and eosin stain of paraffin section, × 400). (B) Nearly all neoplastic cells are proliferating, as demonstrated by reactivity with Ki-67 (frozen section, × 400). (C) Strong CD20 reactivity of BLL cells (frozen section, × 400). (D) Positivity for EBV detected by EBER in situ hybridization (paraffin section, × 400).