Morphology patterns in AML bone marrow biopsies. (A) Scatterplot representing the bone marrow vessel count and Chalkley count of AML at diagnosis, NBM and AML at remission. AML biopsies at diagnosis with a ‘low vessel count’ are displayed below the Y-axis reference line (13 microvessels/hpf), based on the fact that >95% of NBM and AML remission had a vessel count below 13 microvessels/hpf. The X-axis reference line divides AML biopsies at diagnosis with a ‘high vessel count' into two groups according to median Chalkley count of 5.4 in AML at diagnosis. The >95% Chalkley count of the NBM and AML remission biopsies sets an identical cut-off point. Group I, ‘vessel hyperplasia'>5.4; group II, ‘angiogenic sprouting' ≤5.4. Spearman's rho 0.15, p=0.42. (B) Representative picture of immunohistochemical staining for ‘vessel hyperplasia' and (C) ‘angiogenic sprouting'.