Bone Changes Found in Bone Marrow Biopsies

The skeleton function is diversified. It is the instrument for direct locomotion and movement and protects vulnerable tissues. It is important for the homeostasis of minerals, and it shelters the bone marrow which provides the blood elements. The metabolites of Vitamin D, parathyroid hormones, and calcitonin are among the most important regulators in the complex mechanism for the control of the calcium mechanism and the sound condition of bone. These complex mechanisms explain the vulnerability of trabecular bone which is variably affected in many primary or secondary diseases. A bone marrow biopsy can be helpful in diagnosis since morphological changes can be detected before abnormalities are evident on X-rays. Bone remodeling and bone production are typical features in pediatric marrows. However, even in adults bone remodeling is continuing for mechanical support and to provide adequate calcium levels. This bone remodeling in adults is morphologically not noticeable in the figurative sense of peculiar osteoblasts or osteoclasts [1]. The evaluation of trabecular bone on bone marrow biopsies comprises an estimation of the thickness, size, and shape and a general survey of the matrix and cellular components of bony trabeculae. Normally, a structural support for medullary cavities is evident by anastomosing bone spicules. Continuously connected anastomosing bony trabeculae are a pathologic finding. Careful evaluation of the mesenchymal developed osteoblasts and osteocytes and the osteoclasts, which are of hematopoietic origin, is essential. The mononuclear osteoblasts are located in the periphery of trabeculae. In young patients, these cells often form a row along bony trabeculae. Osteoclasts, mostly multinucleated cells, occupy small depressions on the bone’s surface, called Howship lacunae. A patchy distribution of osteoclasts along bony trabeculae is normal in young patients. Mineralized bone predominates and comprises osteocytes. Unmineralized newly formed bone matrix, the osteoid is prominent in young children, but minimal in adults.