Staining of BCLL BM with FVIII-RA.

(A-C) Patients with microvessel area and number at least at the 75th percentile. Note in panel B an enormously dilated neovessel (*), and in panel C, numerous microaneurysmatic dilations of neovessels (arrowheads). (D,E) Patients with lower area and number. Note in panel D, straight, not branched neovessels (arrows), and in panel E, a tumor nodule devoid of neovessels. (F) A control subject with anemia due to vitamin B₁₂ deficiency. In panels D, E, and F, megakaryocytes strongly stained with the FVIII-RA are recognizable. Staining of BM BCLL with VEGF (G) in the same patient as in panel B and (H) in the same patient as in panel D. Original magnification for all panels, × 250.