A 58-year-old man presents with chronic dyspepsia. Upper GI endoscopy reveals nodular thickened folds, erythema, and superficial ulcerations in the gastric antrum. Biopsies show a dense lymphoid infiltrate with lymphoepithelial lesions (atypical small B-cells infiltrating gastric glands). Immunohistochemistry is CD20+, CD5−, CD10−, CD23−, and cyclin D1−. Helicobacter pylori is detected on histology and urea breath test. The diagnosis is gastric MALT lymphoma, as marked **C** in the diagram. Which of the following is the most appropriate first-line management for this patient?
A. R-CHOP chemotherapy regimen for aggressive lymphoma control
B. Involved-field radiotherapy (24–30 Gy in 12–15 fractions) to achieve complete response independent of H. pylori status
C. Rituximab monotherapy followed by observation for residual disease
D. Triple therapy with proton pump inhibitor, clarithromycin, and amoxicillin for 14 days, with expectation of complete histologic remission in 70–80% of cases over 12–18 months
Explanation
Why option 1 is correct
Gastric MALT lymphoma (marked C) at stage IE–IIE with H. pylori positivity is an antigen-driven B-cell malignancy. According to ESMO MALT Lymphoma Guidelines 2024 and Lugano Classification 2014, the first-line management is H. pylori eradication via triple therapy (PPI + clarithromycin + amoxicillin × 14 days, or bismuth quadruple therapy in resistant regions). This achieves complete histologic remission in 70–80% of cases over 12–18 months because removal of the chronic antigenic stimulus (H. pylori) allows the clonal B-cell proliferation to regress. Response is assessed by endoscopy and biopsies at 3, 6, and 12 months using the GELA score.
Why each distractor is wrong
Option 2 (Involved-field radiotherapy): Radiotherapy (24–30 Gy) is reserved for H. pylori-negative cases or those with t(11;18) translocation (API2-MALT1 fusion), which predicts resistance to eradication. This patient is H. pylori-positive with no mention of t(11;18), making eradication the appropriate first step.
Option 3 (Rituximab monotherapy): Rituximab is used for failed local therapy, disseminated disease, or eradication-resistant MALT lymphoma. It is not first-line for H. pylori-positive, localized gastric MALT lymphoma.
Option 4 (R-CHOP): R-CHOP is reserved for aggressive transformation to diffuse large B-cell lymphoma (DLBCL), not for low-grade MALT lymphoma at presentation.
High-YieldNEET PG
Gastric MALT lymphoma is an antigen-driven malignancy; H. pylori eradication is first-line for stage IE–IIE H. pylori-positive disease, achieving 70–80% complete remission. t(11;18) positivity predicts eradication resistance and mandates radiotherapy.
