An Unusual Case of Marginal Zone B-Cell Lymphoma

Abstract

Introduction: To present a case of a marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) presenting as a small bowel stricture. Methods: Case report and literature review. Results: A 49-year-old Ghanaian man with prior atrial septal defect repair and intermittent constipation presented with abdominal pain, nausea, vomiting, and lack of bowel movements, but passing flatus. He denied fevers, night sweats, weight loss, prior abdominal surgery, and any medication use including ACE inhibitors or non-steroidal anti-inflammatory drugs. Labs were unremarkable, CT of the abdomen and pelvis showed a partial small bowel obstruction (SBO) without a clear transition point, and an upper GI series was normal. The patient’s symptoms resolved with conservative management; however, 2 days later he was re-admitted with recurrent symptoms. CT showed recurrent partial SBO with a transition point in the left lower quadrant. Capsule endoscopy subsequently showed few scattered sessile polypoid lesions just proximal to a stricture in the small bowel; the capsule did not pass through this area. Double-balloon enteroscopy was pursued and showed a high-grade discrete stricture with erythematous and fibrotic mucosa in the proximal ileum with adjacent nodular, atrophic, and hypervascular mucosa. Pathology revealed Helicobacter pylori (H. pylori) gastritis and marginal zone B-cell lymphoma of MALT. Discussion: Small intestine MALT lymphoma is an uncommon entity seen in about 12.6-18.8% of all primary small intestine lymphomas. There are only a few case reports and case series in the literature describing small intestine MALT lymphoma, which were diagnosed after patients presented with abdominal pain, obscure gastrointestinal bleeding, abdominal distension, gastric outlet obstruction, SBO, intussusception, and perforation. On endoscopy, small intestine MALT lymphoma most commonly presents as ulcerative (66.7%) or polypoid (26.7%) lesions, with only 1 case reported as presenting with a stricture. Compared to other types of small intestine lymphomas, MALT lymphoma overwhelmingly presents at earlier stages and have very favorable prognoses. While gastric MALT lymphoma associated with H. pylori, usually responds with eradication, remission of small intestine MALT lymphoma after H. pylori eradication is less clearly demonstrated, and chemotherapy is often necessary. Conclusions: Although rare, small intestine MALT lymphoma should remain in the differential diagnosis for SBO and small bowel strictures.