Bone marrow neoplastic
Bone marrow - neoplastic myeloid
Myelodysplastic syndromes (MDS)
Isolated del(5q)


Minor changes: 25 March 2021

Copyright: 2002-2021, PathologyOutlines.com, Inc.

PubMed Search: Isolated del(5q) [TIAB]

Natasha Iranzad, M.D.
Endi Wang, M.D., Ph.D.
Page views in 2020: 815
Page views in 2021 to date: 360
Cite this page: Iranzad N, Wang E. Isolated del(5q). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/myeloproliferative5qminus.html. Accessed April 18th, 2021.
Definition / general
  • Myelodysplastic syndrome (MDS) characterized by anemia with or without other cytopenias or thrombocytosis in conjunction with chromosome 5q deletion with or without one additional cytogenetic abnormality apart from monosomy 7 or del(7q)
  • Myeloblasts represent < 5% of bone marrow cellularity and < 1% of peripheral blood leukocytes
Essential features
Terminology
  • MDS with 5q deletion
  • 5q minus syndrome
ICD coding
  • ICD-O: 9986/3 - myelodysplastic syndrome associated with isolated del(5q)
Epidemiology
  • F > M
  • Adults, median age approximately 60 - 70 years
Sites
  • Blood and bone marrow
Pathophysiology
Etiology
  • Unknown at this time
Clinical features
Diagnosis
Laboratory
  • Repetitive with clinical features and diagnosis headings
Prognostic factors
Case reports
Treatment
Microscopic (histologic) description
  • Blast count must be < 5% in bone marrow
  • Bone marrow cellularity typically hyper to normocellular (Leukemia 2004;18:113)
  • Megakaryocyte hyperplasia
  • Megakaryocytes with nonlobated and hypolobated nuclei
  • Erythroid hypoplasia
  • Dysgranulopoiesis is uncommon
Microscopic (histologic) images

Contributed by Natasha Iranzad, M.D.

Normocellular bone marrow

Megakaryocyte dysplasia

CD61

Cytology description
  • Ring sideroblasts may be present
  • Auer rods must be absent
Cytology images

Contributed by Natasha Iranzad, M.D.

Megakaryocyte dysplasia

Peripheral smear description
  • Blast percentage must be < 1%
Positive stains
  • CD61 highlights increased / dysplastic megakaryocytes
Flow cytometry description
  • No findings specific to this entity
  • Myeloblasts with aberrant phenotype may be detected
Molecular / cytogenetics description
  • Repetitive with diagnosis heading
Molecular / cytogenetics images

Images hosted on other servers:

Karyogram with del(5q)

Sample pathology report
  • Bone marrow, aspirate smear, touch imprint, clot and core biopsy:
    • Normocellular bone marrow (30%) with megakaryocyte dysplasia
    • 3% bone marrow blasts (see comment)
    • Comment: The presence of dysplastic micromegakaryocytes in this patient with longstanding macrocytic anemia is concerning for myelodysplastic syndrome with single lineage dysplasia (MDS SLD). However, a normocellular marrow would be highly unusual for this diagnosis as MDS typically presents with hypercellularity and rarely with hypocellularity. Thus, a definitive diagnosis of MDS cannot be made at this time without evidence of myeloid clonality, increased blasts or hyper / hypocellularity. Correlation with the pending chromosome analysis and FISH studies are required to establish clonality. In addition, myeloid NGS studies may be diagnostically useful to provide evidence of clonality with additional prognostic or potentially therapeutic information; this test may be performed on the peripheral blood if clinically indicated. The corresponding flow cytometric analysis did not detect any phenotypic abnormalities in myeloid or monocytic lineages or increase in blasts, in keeping with the morphologic findings.

FISH - MDS panel:
  • Interpretation
    • 18.5% of cells showed deletion of 5q (EGR1) by interphase FISH. No evidence of numeric abnormalities or deletions involving chromosomes 7, 8 or 20 observed by interphase FISH. Correlation with other laboratory and clinical information is recommended.
  • nuc ish (D5S721/D5S23x2,EGR1x1)[37/200]
  • nuc ish (D7Z1,D7S486)x2[200]
  • nuc ish (D8Z2,D20S108)x2[199]

Summary table:
Locus Result
Monosomy 5/5q- 18.5% deletion 5q
Monosomy 7/7q- within normal limits
Trisomy 8 within normal limits
Deletion of 20q within normal limits

Chromosome analysis:
  • Interpretation
    • 46,XX,del(5)(q12q33)[4]/46,XX[14]
    • Abnormal clone with deletion 5q in 4/20 cells, consistent with concurrent interphase FISH analysis showing 18.5% of cells with deletion 5q (EGR1). Please see the Objective Findings section for details. Evaluation for an acquired TP53 mutation is recommended in patients with MDS with isolated del(5q) to help identify an adverse prognostic subgroup in this generally favorable prognosis MDS entity. Correlation with other laboratory and clinical information is recommended. (Blood 2016;127:2391)
Differential diagnosis
  • Myelodysplastic syndrome (MDS), unclassifiable (Blood 2016;127:2391):
    • Diagnosis of exclusion
    • Cases otherwise meeting criteria for MDS with del(5q) but with 1% blasts on peripheral blood smear on ≥ 2 occasions or pancytopenia, defined as:
      • Hemoglobin < 10 g/dL
      • Absolute neutrophil count < 1.8 x 109/L
      • Platelet count < 100 x 10109/L
  • MDS with excess blasts (EB):
    • As the name suggests, with 2 distinct subcategories depending on the blast count:
      • MDS EB1
        • 5 - 9% blasts in bone marrow
        • 2 - 4% blasts in peripheral blood
      • MDS EB2
        • 10 - 19% blasts in bone marrow
        • 5 - 19% blasts in peripheral blood
  • MDS with single / multilineage dysplasia:
    • Lacks characteristic 5q deletion
  • MDS with ring sideroblasts:
    • Lacks characteristic 5q deletion
    • Ring sideroblasts can be seen in both
    • SF3B1 mutation can be seen in both
Board review style question #1

A 73 year old woman presents with macrocytic anemia and fatigue. Nutritional deficiency as a cause of her anemia has been ruled out clinically. Bone marrow biopsy shows a normocellular marrow. Aspirate smear shows the findings seen above. On chromosomal analysis, the patient is found to have isolated del(5q).

Which of the following is true about this disease?

  1. Approximately 40% of patients progress to AML
  2. Monosomy 7 is commonly seen in this entity
  3. SF3B1 mutation excludes the diagnosis
  4. TP53 mutation is associated with shorter overall survival
Board review style answer #1
D. TP53 mutation is associated with shorter overall survival

Comment Here

Reference: Isolated del(5q)
Back to top
Image 01 Image 02