Abstract

Objective: To critically analyze the clinical decisions adopted in two cases of gastric cancer with simultaneous colonic lesions, and to compare them with current diagnostic and therapeutic approaches. Materials and Methods: Two clinical cases of patients with gastric adenocarcinoma and synchronous colonic lesions are presented. Clinical, imaging, endoscopic, histopathological, and immunohistochemical findings were evaluated, along with the therapeutic decisions. Results: In the first case, the local involve-ment of a synchronous colon tumor was analyzed. In the second, a synchronous colon lesion was shown to be metastatic when confirmed by immunohistochemistry. Discussion and Conclusion: Diagnosing simultaneous gastric and colonic lesions is a complex clinical challenge, particularly when distinguishing between synchronous tumors and colonic metastases from gastric cancer. This distinction determines different therapeutic strategies. Immunohistochemistry is essential when clinical, endoscopic, or imaging findings are inconclusive. The rarity of these cases limits the development of evidence-based guidelines. © 2025, Sociedad de Cirujanos de Chile. All rights reserved.