Synchronous adenocarcinoma of the transverse colon and gastroesophageal junction: a case report.

Introduction: Esophageal cancer is a malignancy with a rapidly increasing incidence in recent decades. The presence of a second synchronous tumor poses challenges when a curative approach is offered. Case presentation: We report a case of a 68-year-old Caucasian male diagnosed with synchronous adenocarcinomas of the transverse colon and the gastroesophageal junction (GEJ), Siewert Type II. The diagnosis followed the presentation of dysphagia and was confirmed through esophagogastroduodenoscopy and colonoscopy. The patient underwent a staging work-up. This has revealed no distant metastases, leading to a decision for curative treatment with multimodal therapy. Neoadjuvant chemotherapy with the FLOT regimen was administered, followed by thoracoabdominal esophagectomy and extended right hemicolectomy. Histopathological and molecular profiling analyses revealed that the tumor of the colon was a metastasis of the GEJ tumor. Clinical discussion: This case demonstrates the diagnostic and therapeutic challenges posed by rare metastatic pattern of the GEJ. Despite thorough preoperative staging, the metastatic nature of the colonic lesion was only revealed postoperatively in our case. This emphasizes the need for molecular profiling in selected cases to enhance diagnostic accuracy and guide treatment decisions more effectively. Conclusion: Colonic metastases from esophageal cancer are exceedingly rare, with only a few cases reported. In this case, according to the postoperative staging (M1) a palliative chemotherapy might have been more appropriate. This case highlights the importance of comprehensive diagnostic workups and the need for molecular profiling of synchronous lesions. Molecular diagnostic may be considered as a part of decision-making, as it can significantly impact treatment strategies and outcomes.