WHO MDS CLASSIFICATION SUBTYPE

MDS WITH RING SIDEROBLASTS
(MDS-RS)

Normal

Red Blood Cells

Abnormal

Red Blood Cells

Normal

White Blood Cells

Abnormal

White Blood Cells

Normal

Platelets

Abnormal

Platelets

Blasts

MDS WITH RING SIDEROBLASTS (MDS-RS)

MDS-RS exhibits a low number of one or more types of blood cells in the bloodstream and bone marrow. At least 15% of immature red blood cell precursors (contain a nucleus) in the bone marrow show rings of iron called ring sideroblasts. Less than 5% of cells in the bone marrow are blast cells.

There are 2 types of MDS-RS:

MDS-RS and Single Lineage Dysplasia (MDS-RS-SLD): has the same characteristics as MDS-SLD; where only one type of blood cell has at least 10% of the cells that look abnormal (dysplasia) but this subtype also has ring sideroblasts on the red blood cell precursors.

MDS-RS and Multilineage Dysplasia (MDS-RS-MLD): has the same characteristics as MDS-MLD; where two or more types of blood cell has at least 10% of the cells that look abnormal (dysplasia) but this subtype also has ring sideroblasts.