A Polypoid Mucosa-Associated Lymphoid Tissue Lymphoma of the Stomach Treated with Endoscopic Polypectomy
A 34-year-old woman visited our hospital for the management of a gastric polyp detected by an upper gastrointestinal endoscopy recently performed at a private clinic during a routine medical examination. She had no record of medical illness other than a history of uterine myomectomy at our hospital. She was asymptomatic, and her physical examination did not reveal any abnormality. She underwent upper gastrointestinal endoscopy, and a 2.5-cm polypoid lesion was found on the great curvature side of the upper body of the stomach (). Biopsy was performed. The pathologic review was suggestive of early-stage marginal zone B-cell lymphoma of MALT type. The tissue was also positive for H. pylori on Giemsa staining. Her laboratory data were as follows: white blood cells, 7,710/mm3 (neutrophil 58.7%, lymphocyte 32.6%, monocyte 5.5%); hemoglobin, 14.1 g/dL; platelets, 176,000/mm3; total protein, 6.1 g/dL; albumin, 3.7 g/dL; total bilirubin, 0.7 mg/dL; aspartate aminotransferase, 20 IU/L; alanine aminotransferase, 21 IU/L; alkaline phosphatase, 41 IU/L; blood urea nitrogen, 11.4 mg/dL; creatinine, 0.83 mg/dL; sodium, 143 mEq/L; potassium, 4.0 mEq/L; chloride, 107 mEq/L; and lactate dehydrogenase, 304 IU/L. An abdominal computed tomography (CT) showed a 1.8-cm polypoid lesion with minimal stalk in the high body of the stomach. No other abnormal findings, including lymph node enlargement, were noted (). Bone marrow examination revealed no abnormal finding.\nAs the initial treatment, H. pylori eradication was performed with a 2-week course of amoxicillin (2×1,000 mg daily), clarithromycin (2×500 mg daily), and rabeprazole (10 mg daily). The eradication was successful, as confirmed by Giemsa staining in the follow-up endoscopy. However, on endoscopy 6 months later, there was no change in the size and morphology of the polypoid MALT lymphoma lesion. Multiple specimens were obtained, and the pathologic evaluation showed the same result of marginal zone B-cell lymphoma of MALT type. We also performed abdominal CT and positron emission tomography but found no systemic lymphoma involvement.\nTo confirm the diagnosis of low-grade lymphoma and exclude the possibility of high-grade lymphoma, we decided to perform polypectomy, which allows collection of enough tissue specimens including the submucosal layer. The lymphoma was removed en bloc, endoscopically with a snare (), after submucosal injection of hypertonic saline. No complication occurred. The final pathologic diagnosis was marginal zone B-cell lymphoma of MALT type, polypoid (). The lymphoma was 1.8×1.3 cm in size and confined to the submucosal layer. The lateral and basal resection margin was clear. At follow-up endoscopy 6 months after polypectomy, a linear whitish scar was observed without evidence of recurrence (). She has been followed up for 3 years without recurrence.