Which cytogenetic finding in adult B-cell acute lymphoblastic leukemia carries the worst prognosis?

• A t(9;22)(q34;q11.2) BCR-ABL1 ✓
• B t(12;21)(p13;q22) ETV6-RUNX1
• C Hyperdiploidy (>50 chromosomes)
• D del(9p) affecting CDKN2A

Explanation

Philadelphia chromosome positive ALL, most common in adults, was historically the poorest risk cytogenetic group in B-ALL because BCR-ABL1 drives constitutive tyrosine kinase signaling; TKI-based regimens have improved outcomes but it remains an adverse marker. Hyperdiploidy and ETV6-RUNX1 are favorable findings seen mainly in childhood ALL. del(9p)/CDKN2C loss is adverse but less classically emphasized than Ph positivity.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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