A Broad Scope of Differentials: Helicobacter pylori-Associated Chronic Gastritis Mimicking a Gastrointestinal Stromal Tumor

Chronic gastritis is a common manifestation of Helicobacter pylori infection. Clinical presentations can range from epigastric discomfort to gastrointestinal bleeding. The clinical course and gross endoscopic findings can mimic alternative diagnoses such as gastric adenocarcinoma and gastrointestinal stromal tumors (GISTs). We report a case of H. pylori-associated chronic gastritis that initially presented with frank melena. Subsequent blood tests demonstrated a drop in hemoglobin and a rise in serum urea. The case was managed according to the hospital's upper gastrointestinal bleed protocols. The next day, endoscopy demonstrated a large polypoidal mass in the gastric antrum suspicious for GIST. However, subsequent biopsy and histological examination showed lymphoid aggregates and active inflammation with comma-shaped bacilli consistent with H. pylori infection. The case was subsequently managed with triple eradication therapy. This case underscores the value of prompt management of upper gastrointestinal bleeding and the need to validate diagnoses with definitive modalities to optimize long-term management.