Primary gastric non-Hodgkin's lymphoma: requirements for diagnosis and staging

Tumor stage and histological grading (low grade vs. high grade) determine the prognostic outcome of primary gastric mucosa-associated lymphoid tissue (MALT)-type non-Hodgkin's lymphoma (NHL). Any diagnostic uncertainty of clinical staging may have potentially important therapeutic implications, especially if a non-surgical approach is favored. Diagnostic procedures for evaluation of gastric lymphoma include gastrointestinal endoscopy, endoscopic ultrasound of the upper gastrointestinal tract, conventional abdominal and cervical ultrasound, thoracic and abdominal computed tomography (CT) scans and bone marrow biopsy. In the present overview, the value of clinical diagnostic procedures is discussed with respect to clinical and endoscopic criteria which may be helpful for evaluation of gastric NHL. Furthermore, clinical staging methods such as endoscopic ultrasound are assessed which may allow pre-operative determination of tumor and lymph-node stage. These novel approaches are compared with the gold standard of pathohistological analysis. In conclusion, the diagnostic procedures presented appear to be helpful for establishing an early diagnosis, however, innovative methods such as endoscopic-bioptic mapping of the stomach and ultrasound-guided fine-needle biopsy techniques may improve pre-therapeutical work-up.