Co-expression of VEGF, Flt-1/VEGFR-1, and myeloperoxidase in a cluster of leukemic blasts (ALIP) in a patient with RAEB.

(upper left) Hematoxylin and eosin staining demonstrating a cluster of ALIP. (upper right) IHC staining for myeloperoxidase (MPO) demonstrating strong expression in ALIP clusters. (lower left) IHC staining demonstrating expression of the Flt-1/VEGFR-1 receptor in a cluster of ALIP cells. (lower right) IHC demonstration of co-expression of VEGF protein in the same cluster of ALIP cells (1000 × magnification).