Myelodysplastic syndromes - classification

Last updated: Thursday, 23, December, 2010

A group of clonal disorders which are characterised by dysplasia and ineffective haematopoiesis in one or more of the major myelod cell lines. There may be an increase of myeloblasts but the number is <20%.

Myelodysplastic syndromes are clonal disorders with a variable risk of progression to acute myeloid leukaemia (AML) and bone marrow failure. The term 'myelodysplastic syndrome' needs to be distinguished from the descriptive terms 'myelodysplasia' and 'dysplastic changes', which may be used in describing bone marrow changes and do not have as specific a meaning.

See also Chronic leukaemia

ClassificationAppropriate Tests

FBC, blood film,  differential WCC. Bone marrow aspiration and trephine biopsy with cytogenetics.

The World Health Organization (WHO) classification replaces the older French-American-British (FAB) classification.

Refractory anaemia

Refractory anaemia with ring sideroblasts (RARS)

See also Sideroblastic anaemia.

Refractory cytopenia with multilineage dysplasia (RCMD)

Refractory cytopenia with multilineage dysplasia and ringed sideroblasts (RCMD-RS)

Refractory anaemia with excess blasts -1 (RAEB-1)

Refractory anaemia with excess blasts -1 (RAEB-2)

Myelodysplastic syndrome unclassified (MDS-U)

MDS associated with an isolated del(5q) chromosomal abnormality

The WHO has created a new category:

Myelodysplastic/myeloproliferative diseases (MDS/MPD)

See also Monocytosis.

  • Juvenile myelomonocytic leukaemia
  • Myelodysplastic/myeloproliferative disease, unclassifiable