FFinalistSouthampton · 2027
Gastroenterology
AKT · Gastroenterology/Oesophagus & stomach

Gastric MALT lymphoma

Helicobacter pylori-driven marginal-zone B-cell lymphoma of gastric mucosa-associated lymphoid tissue (MALT)

Overview

A low-grade (usually indolent) extranodal marginal-zone B-cell lymphoma arising in gastric MALT, the great majority driven by chronic Helicobacter pylori infection. The high-yield point: localised H. pylori-positive disease regresses with eradication therapy alone in most cases — so you eradicate first and confirm regression endoscopically.

Recognise

  • Non-specific dyspepsia, epigastric pain, early satiety, weight loss; iron-deficiency anaemia / occult GI bleeding
  • Strong H. pylori association; usually localised low-grade disease at presentation
  • Endoscopy: gastritis, erosions, ulceration or a mass; biopsy shows lymphoepithelial lesions + monoclonal B cells

Red flags

  • B symptoms, bulky/advanced disease, or histologic transformation to diffuse large B-cell lymphoma → systemic chemo-immunotherapy
  • t(11;18) translocation predicts FAILURE to respond to H. pylori eradication

Differentials & how to tell them apart

Peptic ulcer disease / H. pylori gastritisshares H. pylori cause but no monoclonal lymphoid infiltrate on biopsy
Gastric adenocarcinomaepithelial malignancy (signet-ring/glandular) — different histology and management
Functional dyspepsianormal endoscopy/biopsy

Investigations

OGD + multiple biopsies (lymphoepithelial lesions, immunohistochemistry/clonality); H. pylori testing (histology/urea breath/stool antigen); t(11;18) FISH; staging (CT, EUS for depth, bone marrow if indicated).

Management

H. pylori eradication therapy (first-line for localised H. pylori-positive disease)

  1. 1Confirm histology, stage, and test for H. pylori and t(11;18). For localised H. pylori-positive disease → eradication therapy, then endoscopic surveillance for histologic regression.Gate: If H. pylori-negative, eradication fails, t(11;18)-positive, or there is high-grade transformation → radiotherapy or rituximab-based therapy, NOT repeated eradication.
  2. 2Radiotherapy for localised eradication-refractory disease; rituximab ± chemotherapy for advanced/transformed disease. Long-term endoscopic follow-up.
H. pylori eradication therapy — FIRST-LINE for localised H. pylori-positive disease — induces remission in ~70–80%
Radiotherapy — if H. pylori-negative, eradication fails, or t(11;18)-positive non-responder; localised disease
Rituximab ± chemotherapy — advanced-stage, refractory, or transformed (DLBCL) disease

Key points

Gastric low-grade marginal-zone lymphoma with H. pylori = MALToma → eradicate H. pylori first and confirm regression; t(11;18) marks the patients who won't respond and need radiotherapy/rituximab.

Monitor & prognosis

Serial endoscopy + biopsy to confirm and sustain regression after eradication.

Excellent for localised H. pylori-driven disease; worse with t(11;18) or transformation.

Source: BSG; StatPearls