Long-term follow up of gastric low-grade mucosa-associated lymphoid tissue lymphoma by endosonography emphasizing the application of a miniature ultrasound probe.

BACKGROUND AND AIMS: Endoscopic ultrasonography (EUS) is a useful tool for the evaluation of gastric wall infiltration including gastric lymphoma. The aims of this study were to characterize gastric low-grade mucosa-associated lymphoid tissue (MALT) lymphoma according to EUS findings and to evaluate the role of a miniature ultrasound probe in the long-term follow up. METHODS: From January 1994 to March 2002, 20 patients were proven to have gastric low-grade MALT lymphoma. Endoscopic ultrasonography was performed with a conventional echoprobe and/or a miniature ultrasound probe for initial staging and a miniature ultrasound probe was performed during follow up. All patients positive for Helicobacter pylori received a 2-week course of omeprazole, amoxicillin and clarithromycin. RESULTS: Helicobacter pylori infection was found in 17 (85%) patients. In all patients, H. pylori was eradicated after treatment. Initial EUS showed significantly greater wall thickness (6.1 +/- 3.0 mm) in MALT lymphoma patients when compared with control (2.8 +/- 0.3 mm). The infiltrative patterns included wall thickening (3.5-14.1 mm) in 18 patients: stage E-I1 in 16 (mucosa and/or submucosa), stage E-I2 in one and stage E-II in one. Complete regression of MALT lymphoma following treatment for H. pylori was noted in 14 patients, with a mean duration of 11.3 +/- 9.1 months. Follow-up miniature ultrasound probe sonography showed comparative reduction in wall thickness (P < 0.05). CONCLUSIONS: Endoscopic ultrasonography plays a valuable role in the initial staging and long-term follow up of gastric low-grade MALT lymphoma. The application of a miniature ultrasound probe enables adequate evaluation in the majority of these patients, with additional benefits.