Endoscopic patterns of primary gastric MALT lymphoma.

Primary low grade B-cell lymphoma of the mucosa associated lymphoid tissue (MALT), is an uncommon malignancy with a prolonged period of localized disease, and a possible transition to a high grade MALT lymphoma. The endoscopic diagnosis is often difficult, because of the various macroscopy patterns. The endoscopic aspects seen in 14 patients diagnosed and treated for primary gastric MALT lymphomas, were reviewed. Four main patterns were recognized: 1/Large ulcerations (n = 6, 42.9%), 2/Polypoid lesion (n = 2, 14.3%), 3/Gastritis with small ulcerations (n = 4, 28.5%), and 4/Atypical mucosal relief (AMR): erythema, nodularity, edematous or infiltrated folds (n = 2, 14.3%). In 10 cases (71%) AMR was associated with another endoscopic pattern. Histologically the tumors were of low grade (n = 11) and high grade (n = 3). On initial endoscopy a diagnosis of malignancy was done in 6 out of the 7 patients (85.7%) with large ulcers and the large polypoid mass; in contrast, an adequate endoscopic diagnosis was made in only 3 out of the 7 patients (42.8%) with ulcerative gastritis, AMR, and the small polypoid lesion. The endoscopic aspect of the latter group, representing 50% of all patients and 63.6% of the group with low grade MALT lymphomas, was indistinguishable from a benign lesion. Therefore it is important to be aware of this entity and perform biopsies in every patients with abnormal endoscopic findings.