What is hematopoietic marrow reconversion?
Reconversion of bone marrow is a reverse process of natural replacement of red marrow by yellow marrow. This process involves the appearance of areas of normal red marrow in the places where yellow marrow occurs, and is reverse of conversion.
What is prominent hematopoietic marrow?
Prominent hematopoietic marrow can occasionally be normal in the subchondral regions of some epiphyses, most often in the distal femur, proximal tibia, and proximal humerus (Fig. 25.8). Although this is often interpreted as evidence of marrow reconversion, it likely represents residual hematopoietic marrow [ 20 ].
Is red marrow reconversion normal?
Objective: Conversion of bone marrow in the extremities from red to yellow is a normal maturation process. Marrow reconversion is present when expected yellow marrow is replaced with active red marrow, and it tends to occur at times of physiologic stress.
What triggers hematopoiesis?
The cells of the hematopoietic (blood-forming) system in the bone marrow do so upon receipt of a signal by a hormone called erythropoietin, or Epo for short. This hormone is produced mainly by the kidney that increases the Epo level by up to a thousand-fold as a response to falling oxygen saturation of the blood.
What is conversion and reconversion of red bone marrow?
Conversion and Reconversion At birth, the whole skeleton is filled with red bone marrow. Physiological conversion of red into yellow bone marrow, lasting for the whole childhood until adulthood and has a constant, predictable pattern in the whole skeleton as well as in individual bones. The entire process is completed by the age of 25 years.
Is there reconversion of yellow marrow to red marrow in epiphyses?
Note that there has even been some reconversion of yellow marrow to red marrow in the epiphyses. Generally, reconversion will become evident in the distal metaphyses of long bones before it has been completed in the diaphyses.
Which physical findings are characteristic of bone marrow reconversion?
Generally, reconversion will become evident in the distal metaphyses of long bones before it has been completed in the diaphyses. Some patients without known bone marrow disorders can display evidence of expanded red marrow fractions in the axial and appendicular skeleton.
Is residual hematopoietic marrow present in the proximal humeral metaphysis?
Residual hematopoietic marrow was present within the proximal humeral metaphysis in 99% of patients and extended into the epiphysis in 62%. Epiphyseal hematopoietic marrow was more prominent in female subjects (P = .015) and showed correlation with prominence of hematopoietic marrow within the proximal humeral metaphysis (P = .01).