Diagnostic endoscopic submucosal dissection in the diagnosis of biopsy‐missed gastric mucosa‐associated lymphoid tissue lymphoma.

F, NBI shows scar at the site of resection at 11 months after chemotherapy gl Both of our cases underwent gastroscopy for more than four times but MALT lymphoma could not be diagnosed via biopsy or magnifying endoscopy. Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade B-cell non-Hodgkin lymphoma that is most incident in the stomach.1 The treatment for MALT lymphoma is closely related to the type and stage of the lymphoma as well as patient's I Helicobacter pylori i ( I H. pylori i ) infection status.2 Gastric mapping procedure based on a large number of biopsies is highly recommended for an accurate diagnosis, typing and staging of MALT lymphoma,2 although studies have shown that some features under the magnifying endoscopy indicate a gastric lymphoma.3-6 However, these malignant features, some of which originate from the submucosa, tend to be easily overlooked. Considering the variety of its appearance under endoscopy and the difficulty of diagnosing gastric lymphoma even using a magnifying endoscopy, biopsy is necessary for the diagnosis of the lesions. Five biopsy specimens from the surface and deeper layer of the lesion were obtained, and histologic examination showed suspected MALT and atypical hyperplasia of the lymphatic tissue, as diagnosed with immunohistochemistry (IHC). [Extracted from the article]