Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 39-11: Gastric Lymphoma + Key Features Download Section PDF Listen +++ ++ Second most common gastric malignancy, 3–5% of gastric cancers More than 95% are non-Hodgkin B-cell lymphomas consisting of mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma Gastric T-cell lymphoma, associated with HTLV-1 infection, is rare and makes up 7% of primary gastric lymphomas Infection with Helicobacter pylori is an important risk factor for primary gastric lymphoma > 90% of low-grade primary gastric lymphomas are associated with H pylori + Clinical Findings Download Section PDF Listen +++ ++ Dyspepsia Abdominal pain Weight loss Upper GI bleeding Anemia + Diagnosis Download Section PDF Listen +++ ++ Endoscopic ultrasonography is the most sensitive test for determining the level of invasion and presence of perigastric lymphadenopathy CT scanning of chest, abdomen, and pelvis useful in staging For patients with diffuse large B-cell lymphomas involving the stomach, the following may be required for staging and management Combination PET-CT imaging Bone marrow biopsy with aspirate Tumor lysis laboratory tests Viral hepatitis and HIV serologies The Lugano staging system is most frequent used for gastric MALT lymphomas Stage I is confined to the GI tract Stage II involves local or regional lymph nodes Stage IIE has invasion of adjacent organs or tissues Stage IV has distant metastases There is no stage III + Treatment Download Section PDF Listen +++ ++ Primary low-grade gastric lymphomas Usually localized to the stomach wall (stage I) or perigastric lymph nodes (stage IIE1) Have an excellent prognosis After successful H pylori eradication, complete lymphoma regression occurs in ~75% of cases of stage IE low-grade lymphoma and in ~55% with stage IIE low-grade lymphoma MALT-type lymphomas Patients who are not infected with H pylori or do not respond to eradication therapy can be treated successfully with radiation therapy (or with rituximab if not a candidate for radiation) However, hepatitis B reactivation can occur with rituximab, including fatal cases of fulminant hepatitis Surgical resection is no longer recommended because of a low risk of perforation with either radiation therapy or chemotherapy Long-term survival of primary gastric lymphoma for stage I is > 90% and for stage II, 35–65% Diffuse large B-cell lymphoma Surgery has been associated with a better prognosis than conservative treatment Usually presents at an advanced stage with widely disseminated disease and is treated according to stage and subtype of lymphoma