Bone marrow neoplastic

• 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

Contributed by Natasha Iranzad, M.D.

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• 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 4/18 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)

• Swerdlow: WHO Classification of Tumors of Haematopoietic and Lymphoid Tissues, 4th Edition, 2017

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

D. TP53 mutation is associated with shorter overall survival

Comment Here

Reference: Isolated del(5q)