Lymphoma, Gastric

Key Features

• 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

• Dyspepsia

• Abdominal pain

• Weight loss

• Upper GI bleeding

• Anemia

Diagnosis

• 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

• 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