[Morphofunctional characteristics of stromal structures of bone marrow in aplastic anemia patients].

Stromal structures of the bone marrow in 22 patients with aplastic anemia (AA) were studied histophotometrically. A significant increase of the fat tissue volume and a decrease of hematopoietic tissue volume were observed. Bone tissue volume was significantly increased in 81.8% of patients, the number of endosteal cells was increased in all the patients and that of reticular cells in one third of them. The conclusion is made that hematopoietic microenvironment of the bone is not a determining factor in the majority of AA patients. Excessive bone formation might be one of the mechanisms of aplasia development.