[Low-grade mucosa-associated lymphoid tissue lymphoma of stomach]

Stomach is the most common site of primary extranodal lymphoma. Mucosa-associated lymphoid tissue (MALT) lymphoma is a unique type of extranodal lymphoma which is associated with Helicobacter pylori (H. pylori). The development of low-grade MALT lymphoma of stomach is dependent on H. pylori. A transformed clone carrying the translocation t(11;18)(q21;q21) forms a MALT lymphoma, the growth of which is independent of H. pylori and will not respond to bacterial eradication. And inactivation of the tumor suppressor genes, p53 can lead to high-grade transformation. Endoscopic ultrasound (EUS) is essential to document the extent of disease and is superior to CT scan in the detection of spread to perigastric lymph nodes and follow-up EUS may determine the response to therapy and detect the relapse in early phase. Lesions that are confined to the mucosa or submucosa of gastric wall can be successfully treated with H. pylori eradication. Those low-grade MALT lymphomas that are not H. pylori positive or do not respond to antibiotic therapy can be treated with surgery, radiation, or chemotherapy. Follow-up is critical in all patients who have been treated with H. pylori eradication and consists of multiple endoscopic biopsies and EUS.