A jaw mass biopsy from an 8-year-old boy shows sheets of intermediate-sized lymphoid cells with round nuclei, multiple nucleoli, and abundant apoptosis. Scattered pale macrophages phagocytosing debris create a starry-sky appearance. The underlying molecular event is:
- A Constitutive JAK-STAT signalling through JAK2 V617F
- B Overexpression of BCL2 blocking apoptosis
- C Dysregulation of MYC by translocation to the IGH locus ✓
- D Loss of TP53 by 17p deletion
Correct answer: C. Dysregulation of MYC by translocation to the IGH locus
Explanation
The starry-sky pattern from tingible-body macrophages plus intermediate-sized blasts is endemic Burkitt lymphoma, driven by translocation of MYC on chromosome 8 to the IGH heavy-chain locus on chromosome 14, t(8;14). This forces constitutive MYC expression and drives proliferation with a very high fraction of cells in cycle. BCL2 overexpression defines follicular lymphoma and is characteristically absent in Burkitt, helping distinguish it from double-hit 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.