Upper Gastrointestinal Bleeding Secondary to Gastric Invasion by Diffuse Large B-cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma subtype. We present a case of an 80-year-old male with upper gastrointestinal bleeding (UGIB), ultimately diagnosed with DLBCL involving the liver, gallbladder, inferior vena cava, and stomach, leading to a large gastric ulcer. Despite initial suspicion of alcohol-related UGIB, imaging revealed multiple masses with extranodal lymphoma involvement. Endoscopic hemostasis was attempted but was complicated by tumor-induced neovascularization. This case highlights a rare cause of UGIB and underscores the challenges in diagnosis and management of malignancy-induced bleeding.