Laboratory Studies for Gastric Lymphoma Workup and Staging
For gastric lymphoma workup and staging, obtain complete blood counts, comprehensive metabolic panel (renal and liver function), lactate dehydrogenase, β2-microglobulin, serum protein immunofixation, HIV serology, hepatitis B and C serology, and perform bone marrow aspirate and biopsy 1.
Essential Laboratory Tests
The ESMO guidelines provide clear direction on the laboratory workup required for gastric lymphoma staging 1:
Basic Hematologic and Biochemical Studies
- Complete blood counts - to assess for cytopenias or lymphocytosis
- Comprehensive metabolic panel including:
- Renal function assessment
- Liver function tests
- Lactate dehydrogenase (LDH) - prognostic marker for tumor burden
- β2-microglobulin - additional prognostic indicator
Specialized Laboratory Tests
- Serum protein immunofixation - to detect monoclonal proteins
- Infectious disease serology:
- HIV serology
- Hepatitis C virus serology
- Hepatitis B virus serology
These viral serologies are critical as they may influence treatment decisions and prognosis.
Helicobacter pylori Testing
H. pylori status must be definitively established through multiple testing modalities if not demonstrated on histochemistry 1. This is non-negotiable given that H. pylori eradication is first-line therapy for gastric MALT lymphoma regardless of stage.
Testing options include:
- Serology
- Urea breath test
- Stool antigen test
If histochemistry is negative, pursue alternative testing methods to rule out infection definitively.
Bone Marrow Evaluation
Bone marrow aspirate and biopsy is recommended for staging 1. While the 2014 Lugano classification notes that bone marrow biopsy is no longer routine for most diffuse large B-cell lymphomas 2, the ESMO guidelines specifically recommend it for gastric MALT lymphoma staging.
Molecular and Genetic Studies
Fluorescence in situ hybridization (FISH) for t(11;18)(q21;q21) translocation should be performed 1. This molecular test identifies patients unlikely to respond to antibiotic therapy, allowing earlier consideration of alternative treatments like radiotherapy or chemotherapy.
Important Caveats
The laboratory workup must be integrated with:
- Esophagogastroduodenoscopy with multiple biopsies from all gastric regions
- Endoscopic ultrasound for wall infiltration and lymph node assessment
- CT imaging of chest, abdomen, and pelvis
Do not rely on laboratory tests alone - the diagnosis requires histopathological confirmation with immunohistochemistry panel including CD20, CD10, CD5, and cyclin D1 1.
The laboratory studies serve to:
- Establish baseline organ function before treatment
- Identify prognostic factors (LDH, β2-microglobulin)
- Detect systemic involvement (bone marrow)
- Screen for comorbid infections affecting treatment
- Predict treatment response (t(11;18) translocation)