In normal bone marrow, the normoblasts show synchronous maturation between the nucleus and cytoplasm, as well as normal nuclear and cytoplasmic features (refer to the image on the right). In MDS, this is not the case. Dysplastic normoblasts may show:
- Nuclear budding: the nucleus is not round and demonstrates buds
- Internuclear bridging: a nuclear bridge between two normoblasts
- Nuclear fragments: cytoplasmic pieces of nuclear fragments
- Multi-nucleation: normoblasts with multiple nuclei
- Megaloblastoid changes due to asynchronous maturation between the nucleus and cytoplasm
- Karyorrhexis: degenerating normoblasts
- Ring sideroblasts: iron granules surrounding the nucleus in a ring form (see Prussian blue stain image below)
- Cytoplasmic vacuolization: vacuoles present in the cellular cytoplasm
