Iron-Laden Mitochondria in Reticulum Cells of Hypersiderotic Human Bone Marrows

Iron-laden mitochondria were observed in three cases of primary nonhereditary sideroblastic anemia. The cells involved are considered to be a peculiar type of reticulum cell, possibly with erythropoietic potentiality. This feature and the rare presence of iron in mitochondria of reticulum cells which are clearly identifiable as macrophages suggest that an enzymatic defect in hemoglobin synthesis may account for the majority, but probably not all instances, of iron-laden mitochondria.