Gastric lymphoma is the second most common cause of gastric malignancies (2-8%) and the most common primary lymphoma location of the gastrointestinal tract. The vast majority are non-Hodgkin lymphoma, with the most common subtypes being diffuse large B-cell lymphoma (DLBCL) and mucosa-associated lymphoid tissue (MALT) lymphoma. The most characteristic imaging finding is diffuse or segmental gastric wall thickening with preservation of perigastric fat planes; this feature is the most important differentiating finding from adenocarcinoma. The gastric lumen typically remaining patent (luminal obstruction is rare) is another distinguishing feature.
Age Range
40-80
Peak Age
60
Gender
Male predominant
Prevalence
Uncommon
Gastric MALT lymphoma develops through chronic antigenic stimulation from chronic Helicobacter pylori infection triggering mucosa-associated lymphoid tissue (MALT) proliferation; therefore H. pylori eradication can be the primary treatment in early-stage MALT lymphoma. DLBCL can develop through transformation from MALT lymphoma or de novo; it has a more aggressive course requiring chemoimmunotherapy. Lymphoma cells infiltrate the gastric wall transmurally but spread without destroying the stroma unlike adenocarcinoma; therefore perigastric fat planes are preserved and the 'preserved fat plane' finding appears on CT. Submucosal spread of lymphoma causes wall thickening while maintaining gastric lumen flexibility; this explains why luminal stenosis is rare in lymphoma. Due to the distribution of Peyer's patches and mucosal lymphoid tissue, multifocal involvement is common.
The most characteristic and distinguishing finding of gastric lymphoma is preservation of perigastric fat planes despite significant gastric wall thickening. This finding reflects lymphoma's characteristic of infiltrating without destroying the stroma and is the most valuable criterion for differentiation from adenocarcinoma (fat planes obliterated). Additionally, rare luminal obstruction (aneurysmal dilatation) and multifocal involvement support this diagnosis.
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In the arterial phase, [X] mm diffuse/segmental wall thickening with homogeneous, moderate enhancement is noted in the [location] gastric wall.
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In the portal venous phase, gastric wall thickening is more conspicuous with preserved perigastric fat planes, accompanied by retroperitoneal lymphadenopathy.
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Progressive enhancement is noted in gastric wall thickening in the delayed phase; peritoneal or small bowel involvement should be evaluated.
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On MRI, diffuse wall thickening mildly hyperintense on T2W with significant diffusion restriction on DWI is noted in the gastric wall, consistent with lymphoma.
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On PET-CT, intense/moderate FDG uptake with SUVmax: [X] is noted in the gastric wall thickening, consistent with lymphoma.
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On barium study, diffuse thickening of gastric folds and nodular filling defects are noted, with preserved luminal patency consistent with lymphoma.
Criteria
MALT lymphoma is an indolent lymphoma associated with H. pylori. On CT, it shows mild-moderate wall thickening or superficial mucosal thickening. PET-CT FDG uptake may be low (false negative). H. pylori eradication can achieve 60-90% complete remission. t(11;18) translocation predicts antibiotic resistance. Excellent prognosis in stage I-II (90%+ 5-year survival).
Distinct Features
Criteria
DLBCL is the most common subtype of gastric lymphoma with an aggressive course. On CT, it appears as prominent wall thickening, polypoid mass, or ulcerative lesion. PET-CT shows high FDG uptake (SUVmax >10). R-CHOP chemotherapy is standard treatment. 5-year survival is 60-70%. It can develop from MALT lymphoma transformation or de novo.
Distinct Features
Criteria
Mantle cell lymphoma is rare in the stomach but when GI involvement is present, the 'lymphomatous polyposis' pattern (multiple polypoid lesions) is characteristic. On CT, multiple polypoid filling defects are observed. Usually part of systemic disease, isolated gastric involvement is rare. Aggressive course with poor prognosis despite chemotherapy.
Distinct Features
Distinguishing Feature
Distinguishing Feature
Distinguishing Feature
Distinguishing Feature
Urgency
Management
Biopsy
Not NeededFollow-up
MALT lymphoma can be treated with H. pylori eradication (low-grade). DLBCL requires chemotherapy (R-CHOP). Gastric lymphoma generally has a better prognosis than gastric carcinoma.