Bony trabeculae before and after BMT.

Bone biopsy prior to BMT (left panel) shows bony trabeculae to be irregular and increased in number and to contain residual strips of unremodeled cartilage (blue-gray within the pink trabecular bone). Osteoclasts are not increased. The marrow cavity contains trilineage hematopoiesis but is markedly reduced. Post-BMT (right panel), the bony trabeculae are normal with no residual cartilage. The marrow space is expanded by cellular trilineage hematopoiesis. Both illustrations show hematoxylin-eosin–stained sections at 140 ×.