sideroblast

/ˈsɪdərəˌblæst/
noun
  1. A red blood cell precursor in the bone marrow that contains iron granules.
    • Sideroblasts are normally present in small numbers during red blood cell production.
    • A high number of sideroblasts in a blood sample can indicate a medical condition.
    • The doctor examined the bone marrow for abnormal sideroblasts.