Biopsy of a rapidly enlarging jaw mass in a 9-year-old boy shows sheets of intermediate-sized lymphoid cells with numerous apoptotic bodies, interspersed tingible body macrophages producing a starry sky appearance, and a proliferation fraction approaching 100%. The defining molecular event is:
- A MYC activation by juxtaposition to the Ig heavy chain locus via t(8;14) ✓
- B BCL2 overexpression via t(14;18)
- C Cyclin D1 overexpression via t(11;14)
- D ALK fusion via t(2;5)
Correct answer: A. MYC activation by juxtaposition to the Ig heavy chain locus via t(8;14)
Explanation
Burkitt lymphoma is defined by MYC dysregulation, classically t(8;14)(q24;q32) placing MYC beside the immunoglobulin heavy chain enhancer, driving constitutive expression and near-total proliferative activity. Variant translocations involve kappa or lambda light chain loci. t(14;18) with BCL2 characterises follicular lymphoma, t(11;14) with cyclin D1 characterises mantle cell lymphoma, and t(2;5) with ALK characterises anaplastic large cell lymphoma.
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.