MDS/AML del(11)(q14) Share Common Morphological Features Despite Different Chromosomal Breakpoints.

Area of Science:

• Hematology
• Cytogenetics
• Oncology

Background:

• Deletion of the 11q14 region is a rare chromosomal defect (0.6-1.0% incidence) in myelodysplastic syndromes and acute myeloid leukemia (MDS/AML).
• This defect is classified under intermediate risk by the International Prognostic Scoring System.
• No previous fluorescence in situ hybridization (FISH) studies have identified a common breakpoint region (CBR) for this deletion.

Purpose of the Study:

• To investigate the presence of a common breakpoint region (CBR) in patients with MDS/AML harboring an 11q14 deletion using FISH.
• To correlate the cytogenetic findings with morphological features in these patients.

Main Methods:

• FISH analysis was performed on seven MDS/AML patients with 11q14 deletion identified by conventional cytogenetics.
• Bacterial artificial chromosomes and commercial probes were utilized for detailed FISH analysis.

Main Results:

• FISH revealed deletions in five patients and amplifications in two.
• Among the five patients with deletions, three harbored a CBR, while two had more centromeric breakpoints.
• Morphological features observed in these five patients included multilineage dysplasia, blast cells with specific nuclear and cytoplasmic characteristics, and thin Auer bodies.

Conclusions:

• A common breakpoint region (CBR) exists in a subset of MDS/AML patients with 11q14 deletions.
• Distinct morphological features, including multilineage dysplasia in MDS and strongly peroxidase-reactive leukemic blasts in AML, are associated with these deletions, irrespective of the deletion's size.
• These findings contribute to a better understanding of the genetic and morphological landscape of MDS/AML with 11q14 deletions.