Biopsy of a rapidly enlarging jaw mass in a 9-year-old boy shows sheets of intermediate-sized lymphoid cells with round nuclei, multiple small nucleoli, and abundant apoptosis, interspersed with pale-staining macrophages producing a starry-sky appearance. Which molecular event is characteristic of this tumour?
- A Overexpression of BCL2 due to t(14;18)
- B Activation of MYC due to t(8;14) ✓
- C Cyclin D1 overexpression due to t(11;14)
- D ALK fusion due to t(2;5)
Correct answer: B. Activation of MYC due to t(8;14)
Explanation
The starry-sky pattern of tingible-body macrophages among sheets of blasts is endemic Burkitt lymphoma, driven by translocation of MYC on chromosome 8 to the immunoglobulin heavy chain locus via t(8;14), causing constitutive MYC expression and extremely rapid proliferation. BCL2 overexpression from t(14;18) defines follicular lymphoma and would actually counteract the prominent apoptosis that creates the starry-sky appearance, which kills that distractor.
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.