Figure 4.

Histopathological analyses of bone marrow lesion cores indicating a mixed pathology. (a) Diffuse granulation reaction in the marrow compartment. All blood vessels show signs of secondary remodeling with thickened walls. Some vessels show evidence of focal fibrinoid adhesion to the endothelium. (b) High-power view of focal granulation reaction. (c) Regional granulation reaction continuous with a focal fibrinoid reaction with thrombus inclusions. There is evidence of a low-grade inflammation peripheral to the fibrinoid edge. The marked vessel remodeling and the presence of fibrinoid inclusions in the granulation zone are consistent with a focal infarction. (d) Vascular leak with multiple thrombus inclusions. There is fibrinoid occupation and casting of the marrow stroma.