Transmission and scanning electron microscopy study on congenital dyserythropoietic anemia type I.

An ultrastructural study of the aspirated bone marrow of a patient with congenital dyserythropoietic anemia type I is presented. Both in transmission electron microscopy (TEM) and in scanning electron microscopy (SEM) ultrastructural abnormalities of the bone marrow erythroid precursors were seen. These abnormalities in TEM included uneven condensation of chromatin with spongy appearance and alterations of cellular division. The most striking among these alterations were: firstly, the intercellular bridges which were typified by the presence of chromatin and the absence of the midbody and contractile ring and, secondly, the anomalies of the nuclear membrane. Occasionally, autolytic areas within the cytoplasma and iron-laden mitochondria were to be seen. In the SEM the following features were notable: the length of the intercellular bridges, the absence of the central ridge in the midbody area, as well as the scanty number of cytoplasmic blebs on the surface of the bridges.