Normal and Abnormal Bone Marrow R. Paul Guillerman, MD Professor of Radiology Disclosure of Commercial Interest Neither I or a member of my immediate family  have a financial relationship with a commercial organization that may have an interest in the content of this educational activity Topics Normal Marrow Composition, Conversion, and Variants  Marrow Hyperplasia, Reconversion, and Reconstitution  Marrow Infiltration and Deposition Disorders  Marrow Failure and Depletion Disorders  5-year-old, ? normal Normal Marrow Composition, Conversion, and Variants  Composition of Bone Marrow Primal “brain food”  Calorie and nutrient dense  Composition of Bone Marrow Cancellous trabeculae Stromal tissue Hematopoietic cells Fat Red Marrow Composition Active in hematopoiesis  Highly vascularized  Color due to hemoglobin in  erythroid cells Red Marrow Composition Hematopoietic cellularity  diminishes from near 100% at birth to 60% by adulthood Fat content increases with age  By adulthood, composed of 40%  fat Yellow Marrow Composition Minimal hematopoiesis  Paucity of vasculature  Color due to carotenoids in fat  droplets