An Unusual Cause of Upper Gastrointestinal Bleeding in Clinical Practice; A Case Report of Locally Invasive Colon Cancer with Superimposed Actinomycosis

Background: Colon cancer commonly presents with lower gastrointestinal bleeding in symptomatic patients. Upper gastrointestinal bleeding as a symptom of colon cancer is unusual. This case highlights the diagnostic and management challenges of colon cancer masquerading as gastric ulcer with a bleeding complication. Case Presentation: We report the case of a 45-year-old man who presented with passage of melaena stools with associated epigastric pain. Endoscopy revealed gastric ulcer in the greater curvature. Histopathology identified a diffuse adenocarcinoma with superimposed actinomycosis. Intra-operatively the patient was found to have a carcinoma of the transverse colon diffusely infiltrating and ulcerating the stomach in its greater curvature . Patient died from bilateral pulmonary thromboembolism 10 weeks after the surgery. Conclusion: Although rare, colon cancer can present with upper gastrointestinal bleeding. It must be considered as a differential in the work up for a patient passing melaena stool.