A 65-year-old man has lymphocytosis of 80 × 10⁹/L with mature-appearing lymphocytes. Flow cytometry shows CD5+, CD23+, CD19+, dim surface IgM, and CD20 dim. Which genetic abnormality is most commonly associated with a favorable prognosis in this condition?
- A Deletion 17p (TP53)
- B Deletion 13q14 (miR-15a/16-1) ✓
- C Deletion 11q (ATM)
- D Trisomy 12
Correct answer: B. Deletion 13q14 (miR-15a/16-1)
Explanation
This is CLL with the characteristic CD5+/CD23+/CD19+ immunophenotype. Deletion 13q14 (involving the miRNA locus miR-15a/16-1, which normally suppresses BCL2) is the most common cytogenetic abnormality in CLL and, when isolated, carries the most favorable prognosis with longest time-to-treatment. Del 17p and del 11q indicate aggressive disease.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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