Relationship between microvessel counts per ×500 field in adjacent sections of the bone marrow stained for thrombomodulin (TM) or von Willebrand factor (vWF).

For each sample (62 patients with acute myeloid leukemia [AML] and 22 control patients), microvessel density measured by vWF staining was plotted against the microvessel density obtained with TM staining. Significance of the regression analysis was calculated by the Pearson test (r = 0.875, P < .0001).