S4800 Diffuse Large B-Cell Lymphoma: An Uncommon Cause of Upper Gastrointestinal Bleeding—A Case Report

Introduction: Non-Hodgkin Lymphoma (NHL) often affects lymph nodes and extranodal abdominal structures. While gastric involvement may cause upper gastrointestinal (GI) bleeding, massive hemorrhage due to diffuse large B-cell lymphoma (DLBCL) remains exceedingly rare. We present a 62-year-old man with an upper GI bleed caused by gastric DLBCL, underscoring the importance of considering hematologic malignancies in atypical GI hemorrhage. Case Description/Methods: A 62-year-old man with no significant past medical history presented with shortness of breath, chest discomfort, and epigastric pain. He reported dark, tarry stools for 2 months. On arrival, BP was 95/55 mmHg and HR 110 bpm. Hemoglobin was 3.3 g/dL. He was resuscitated with IV fluids and blood transfusions and started on intravenous pantoprazole. Computed tomography angiography of the abdomen/pelvis showed wall thickening of the stomach along the lesser curvature, extending into the antrum/pylorus, with prominent perigastric lymphadenopathy concerning for malignancy. Esophagogastroduodenoscopy (EGD) revealed a necrotic ulcer on the lesser curvature with suspicion of cancer. H. pylori antigen was negative. Biopsies were positive for CD20, PAX5, CD10, and BCL6 which was diagnostic for DLBCL. Fluorescence in situ hybridization for double-hit lymphoma was negative. The patient began treatment with rituximab, cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone (R-CHOP), with good prognosis anticipated. Hemoglobin stabilized at around 8 g/dl and improved after starting therapy. Discussion: Lymphomas often involve nodal and extranodal abdominal structures, with DLBCL being the most common subtype of NHL. Gastric lymphomas usually present with vague symptoms like abdominal pain, dyspepsia, nausea, vomiting, diarrhea, weight loss, or a palpable mass. GI bleeding is a rare presentation, especially with DLBCL. This patient presented with melena, abdominal pain, and symptoms likely due to anemia. Diagnosis is made via biopsy, as imaging lacks specificity. For gastric lesions, biopsies are typically obtained by EGD. Initial treatment for upper GI bleed includes intravenous pantoprazole. If a visible vessel is present, clip placement and argon plasma coagulation may be used. Current management of DLBCL favors immunochemotherapy, with R-CHOP being the standard first-line regimen. Surgery is now reserved for managing complications such as perforation, uncontrolled bleeding, or obstruction.