A 66-year-old man presents with generalized painless lymphadenopathy and anemia. Node biopsy shows a monotonous population of small lymphocytes with irregular, cleaved nuclei arranged around residual germinal centres. Immunophenotype: CD5 positive, CD20 positive, FMC7 positive, CD23 negative, strong nuclear cyclin D1 expression, SOX11 positive. Which cytogenetic abnormality underlies this neoplasm?

• A t(14;18) involving BCL2 and the IgH locus
• B t(8;14) involving MYC and the IgH locus
• C t(11;14) juxtaposing CCND1 with the IgH enhancer ✓
• D del(13q14) as the sole cytogenetic abnormality

Explanation

Mantle cell lymphoma is defined by t(11;14), which places CCND1 under the immunoglobulin heavy chain enhancer, producing constitutive cyclin D1 that drives G1-S transition; nuclear cyclin D1 and SOX11 are its immunologic signature. The tempting distractor is CLL/SLL, which also expresses CD5, but CLL is CD23 positive, has dim surface Ig, lacks cyclin D1, and carries del(13q14) among other changes rather than this translocation.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.