February 2023 – Cytogenetics and Laboratory Genetics & Genomics

By MCL Education • February 10, 2023

A 63-year-old woman presented with a high WBC count and splenomegaly, but no lymphadenopathy. A bone marrow biopsy showed a subset of the neoplastic cells appear positive for SOX11, focal positive for CD5, negative for cyclin D1 and LEF1 and flow was negative for CD200. The overall clinical, morphologic, and immunophenotypic findings are atypical for either CLL or MCL (Figure 1A, 1B, and 1C). FISH was normal for the CLL panel and the CCND1 and IGH gene regions (Figure 1C). 

Figure 1

What test should be performed next to clarify the diagnosis? 

  • Reperform cyclin D1 stain, as there was likely an error.
  • Chromosome analysis to determine if there is hyperdiploidy.
  • CCND2 FISH probe to rule in a possible cyclin D1-negative MCL.
  • Chromosomal microarray to identify any copy number variants and rule out CLL.

The correct answer is ...

CCND2 FISH probe to rule in a possible cyclin D1-negative MCL.

It is reported that CCND2 rearrangements are the most frequent genetic events in cyclin D1-negative MCL. Therefore, FISH for CCDN2 would be the next best step to clarify the diagnosis.

References

  1. Salaverria I, Royo C, Carvajal-Cuenca A, et al. CCND2 rearrangements are the most frequent genetic events in cyclin D1(-) mantle cell lymphoma. Blood. 2013 Feb 21;121(8):1394-1402. doi:10.1182/blood-2012-08-452284

Alaa Koleilat, Ph.D.

Fellow, Laboratory Genetics & Genomics
Mayo Clinic
@koleilat_alaa

Xinjie Xu, Ph.D.

Consultant, Laboratory Genetics & Genomics
Mayo Clinic
Assistant Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine and Science
@XinjieXu

MCL Education

This post was developed by our Education and Technical Publications Team.

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