Gastric mucosa-associated lymphoid tissue lymphoma with a focal high-grade component diagnosed by EUS and endoscopic mucosal resection for histologic evaluation

Successful Endoscopic Resection of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma Unresponsive to Helicobacter pylori Eradication Therapy

Eradication of Helicobacter pylori is the first-line treatment for gastric mucosa-associated lymphoid tissue (MALT) lymphomas; however, lesions may persist in 20% of patients after initial treatment, thereby necessitating the use of an additional therapeutic approach. Other treatment options include radiation therapy, chemotherapy, endoscopic resection, rituximab therapy, or watchful waiting. We present a case of localized gastric MALT lymphoma that did not respond to H. pylori eradication therapy. The patient waited for 12 months but the tumor showed no signs of regression endoscopically. Histologic examination revealed residual MALT lymphoma. The tumor was then successfully treated using endoscopic submucosal dissection and the patient remained disease-free for 4 years. To our knowledge, this is the first case in which a gastric MALT lymphoma was treated with endoscopic submucosal dissection. In conclusion, endoscopic resection may be recommended as second-line therapy for properly selected patients with gastric MALT lymphoma as it is effective and minimally invasive.

Helicobacter pylori infection in gastric mucosa-associated lymphoid tissue lymphoma

Gastrointestinal lymphoma is the most common type of extranodal lymphoma, and most commonly affects the stomach. Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) and diffuse large B-cell lymphoma are the most common histologic types of gastric lymphoma. Despite its increasing incidence, diagnosis of gastric lymphoma is difficult at an earlier stage due to its nonspecific symptoms and endoscopic findings, and, thus, a high index of suspicion, and multiple, deep, repeated biopsies at abnormally and normally appearing sites in the stomach are needed. In addition, testing for Helicobacter pylori (H. pylori) infection and endoscopic ultrasonography to determine the depth of tumor invasion and involvement of regional lymph nodes is essential for predicting response to H. pylori eradication and for assessment of disease progression. In addition, H. pylori infection and MALT lymphoma development are associated, and complete regression of low-grade MALT lymphomas after H. pylori eradication has been demonstrated. Radiotherapy and/or chemotherapy can be used in cases that show poor response to H. pylori eradication, negativity for H. pylori infection, or high-grade lymphoma.

Endoscopic diagnosis and staging of mucosa-associated lymphoid tissue lymphoma

PURPOSE OF REVIEW

The role of endoscopy, including endoscopic ultrasound, in the diagnosis and management of mucosa-associated lymphoid tissue lymphomas of the stomach has evolved steadily in the last two decades. The present review summarizes recent findings and puts them in context with studies on the diagnosis and management of mucosa-associated lymphoid tissue lymphoma published earlier.

RECENT FINDINGS

Several recent studies have emphasized the crucial role of endoscopic ultrasound in treatment planning in patients with gastric mucosa-associated lymphoid tissue lymphoma. This is important as early-stage gastric mucosa-associated lymphoid tissue lymphomas can be managed just by the eradication of Helicobacter pylori by appropriate antibiotic regimens. However, the more advanced lesions are treated with much more invasive treatment regimens involving radical gastrectomy, chemotherapy or radiation, or all.

SUMMARY

Endoscopic ultrasound staging is highly accurate in predicting response to Helicobacter pylori eradication in patients with gastric mucosa-associated lymphoid tissue lymphoma. Normalization of gastric wall thickness and architecture can be used to monitor tumor regression following treatment. Endoscopic ultrasound findings can also be used to identify treatment failures and relapses and can help identify patients who need more aggressive therapy.