Disruption of Marrow Microenvironments in Chronic Lymphocytic Leukemia by High-Resolution Synchrotron Micro-Computed Tomography.

Chronic lymphocytic leukemia (CLL) is associated with increased fracture risk unexplained by standard bone density scans, suggesting underlying microstructural alterations. To investigate this, we used high-resolution synchrotron micro-computed tomography (SRμCT) on bone marrow biopsies from 17 CLL patients, who were stratified into low and high infiltration groups using objective, data-driven clustering. To our knowledge, this is the first report to quantify these changes. High CLL marrow infiltration was associated with a 40.3% reduction in lacuna density and a 101% increase in the normalized adipose surface area-to-volume ratio, a metric indicating greater structural fragmentation. Both changes correlated with leukemic infiltration percentage and showed partial reversal after therapy in a longitudinal case. Furthermore, high CLL burden significantly altered the morphological distributions of the remaining lacunar osteocyte (p < 0.001). We identify a novel marrow remodeling phenotype in CLL characterized by osteocyte depletion and adipose disruption. These changes likely contribute to skeletal fragility and represent potential microstructural biomarkers for assessing marrow health more accurately than conventional imaging.