5q- Syndrome
Definition
- Myelodysplastic syndrome characterized by deletion of 5q as the sole cytogenetic abnormality and no increase in blasts
Alternate Names
- 5q minus syndrome
Diagnostic Criteria
- Deletion of 5q is sole cytogenetic abnormality
- Additional molecular abnormalities may be present
- 5-10% have JAK2V16F mutation
- Loss of Y is allowed (normal age related phenomenon)
- Additional molecular abnormalities may be present
- Peripheral blood blasts <1%, based on 200 leukocyte differential
- Bone marrow blasts <5%, based on 500 nucleated cell differential
- If marrow blasts 5-19%, or Auer rods present, designate as
RAEB
- Poor prognosis
- If marrow blasts 5-19%, or Auer rods present, designate as
RAEB
- Bone marrow megakaryocytic hyperplasia
- Hypolobated or unilobated, small megakaryocytes
- Increased in number
- May loosely cluster
- Normal or increased platelet count
- Frequently abnormal morphology
- Hypolobated or unilobated, small megakaryocytes
- Macrocytic anemia is usually present
- Often with bone marrow erythroid hypoplasia and megaloblastoid differentiation
- Dyssynchronous maturation of nucleus and cytoplasm of erythroid precursors
- Often with bone marrow erythroid hypoplasia and megaloblastoid differentiation
- Dysgranulopoeisis when present may be associated with inferior survival
Dita Gratzinger MD PhD
Tracy I George MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting: 10/23/11