AIM: To emphasize the importance of a detailed observation for incidental simultaneous tumoral masses during surgery for gastrointestinal stromal tumors (GISTs) at any location in the gastrointestinal system. CASE PRESENTATIONS: Case 1: a 39-year-old female patient with an esophageal squamous cell carcinoma and a synchronous small intestinal GIST discovered incidentally during esophagectomy. Case 2: a 73-year-old female patient with a gastric GIST and a synchronous colorectal cancer detected incidentally during gastrectomy. In both cases, immunohistochemical examinations of the resected specimens confirmed the coexistences of GISTs and epithelial malignancies. CONCLUSION: The coexistences of GISTs with epithelial tumors have been increasing in recent years. In any case of a GIST or gastrointestinal adenocarcinoma, the surgeon should be alert to recognize a possible coexistent tumor with different histological origin.
AIM: To emphasize the importance of a detailed observation for incidental simultaneous tumoral masses during surgery for gastrointestinal stromal tumors (GISTs) at any location in the gastrointestinal system. CASE PRESENTATIONS: Case 1: a 39-year-old female patient with an esophageal squamous cell carcinoma and a synchronous small intestinal GIST discovered incidentally during esophagectomy. Case 2: a 73-year-old female patient with a gastric GIST and a synchronous colorectal cancer detected incidentally during gastrectomy. In both cases, immunohistochemical examinations of the resected specimens confirmed the coexistences of GISTs and epithelial malignancies. CONCLUSION: The coexistences of GISTs with epithelial tumors have been increasing in recent years. In any case of a GIST or gastrointestinal adenocarcinoma, the surgeon should be alert to recognize a possible coexistent tumor with different histological origin.