2669 Mucosa-Associated Lymphoid Tissue Lymphoma: Crossing the Borders!

Abstract

INTRODUCTION: Mucosa-associated lymphoid tissue (MALT) lymphoma or MALTomas are responsible for half of the primary gastric lymphomas and up to 8% of B-cell lymphomas. It mostly affects patients in their 5th or 6th decade of life. MALT lymphoma is well known to remain localized in the stomach and to follow a benign course. Despite that gastric MALToma is well defined in the literature, it is rather uncommon to present as a peri-pancreatic mass. Herein, we present the case of a patient with an incidental peri-pancreatic mass diagnosed as an aggressive form of MALT lymphoma. CASE DESCRIPTION/METHODS: A 76-year-old male with hypertension presented to the gastroenterology clinic for the evaluation of peri-pancreatic mass incidentally found during computed tomography (CT) scan performed for renal colic. Physical examination was remarkable for an epigastric fullness with no tenderness. Laboratory tests were remarkable for iron deficiency anemia. CT showed a 7 cm ill-defined soft tissue mass within the pancreaticoduodenal groove abutting the pancreatic head and encasing the gastroduodenal artery suspicious for a pancreatic neoplasm (Figure 1). Endoscopic ultrasound (EUS) showed a hypoechoic heterogeneous mass arising from the gastric wall in close proximity to the pancreas (Figure 2). EUS-guided biopsies were consistent with extra-nodal marginal zone lymphoma of MALT (Figure 3). Gastric biopsies confirmed the presence of MALToma and revealed positive Helicobacter Pylori (HP) infection. Staging workup confirmed extensive bone marrow as well as para-aortic, mediastinal and paratracheal lymph node involvement. The patient received curative HP treatment and was started on bendamustine and rituximab. DISCUSSION: The stomach is the most commonly affected organ by MALT lymphoma. Helicobacter Pylori is a major precursor for the development of gastric MALT lymphoma as up to 90% of affected patients show H.Pylori on stomach biopsies. Chronic HP infection leads to lymphoid tissue proliferation within the stomach and progression towards lymphoma. In this setting, the course is usually indolent with the disease usually confined to the stomach but aggressive tumor behavior has been reported. HP antibiotic eradication remains the first line therapy for early-stage HP positive gastric MALT lymphoma. In other instances, a patient-tailored approach is recommended based on the stage, involved site, HP status and clinical characteristics. Therapeutic options include radiation therapy, chemotherapy and surgery accordingly.