A 25-year-old presents with mediastinal mass, fever, night sweats, and weight loss. LDH is elevated. Biopsy shows large cells with vesicular nuclei and prominent nucleoli in a 'starry sky' pattern with numerous tingible-body macrophages. Cells are BCL-2-negative and show near-100% Ki-67 proliferation index. The translocation most likely responsible is:

• A t(14;18) — BCL2-IGH
• B t(11;14) — BCL1(CCND1)-IGH
• C t(2;5) — NPM-ALK
• D t(8;14) — MYC-IGH ✓

Explanation

The starry sky pattern with >95% Ki-67 proliferation index and BCL-2 negativity in a young patient with a rapidly growing mass is the hallmark of Burkitt lymphoma. The defining translocation is t(8;14)(q24;q32), juxtaposing MYC with the immunoglobulin heavy chain locus, causing dysregulated MYC-driven proliferation. t(14;18) is characteristic of follicular lymphoma; t(11;14) characterizes mantle cell lymphoma; t(2;5) is found in anaplastic large cell lymphoma (ALCL).

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.