A 47-year-old woman with dyspepsia is found to have gastric low-grade B-cell lymphoma of marginal zone (MALT) type. Gastric biopsy confirms Helicobacter pylori infection. Eradication therapy is planned, but which finding predicts failure of antibiotic therapy alone and the need for radiation or systemic treatment?

• A Isolated del(13q14) by FISH
• B Presence of t(8;14) involving MYC
• C Coexisting t(14;18) involving BCL2 and the IgH locus of follicular lymphoma type
• D Presence of t(11;18)(q21;q21) creating an API2-MALT1 fusion gene ✓

Explanation

The API2-MALT1 fusion from t(11;18) activates NF-kB constitutively, making lymphoma growth independent of antigenic stimulation by H. pylori, so these tumours respond poorly or not at all to eradication and require radiotherapy or systemic therapy. In contrast, t(8;14) defines Burkitt lymphoma, and t(14;18) of the follicular type marks BCL2 deregulation; neither is the recognized predictor of antibiotic failure in gastric MALT 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.