Asymptomatic Esophageal Carcinosarcoma Diagnosed Based on Endoscopic Submucosal Dissection Results: A Case Report

Background Esophageal carcinosarcoma is a rare type of esophageal cancer with a characteristic sausage shape that is often detected at an early stage; therefore, the depth of invasion is often submucosal. However, many cases of esophageal carcinosarcoma demonstrate lymphatic metastases, which require surgery. Case We describe the case of a 46‐year‐old female patient who underwent upper gastrointestinal endoscopy that revealed a tumor shadow in the middle thoracic esophagus. The patient did not have symptoms such as dysphagia or chest pain. Subsequent upper gastrointestinal endoscopy with ultrasound and endoscopic submucosal dissection revealed carcinoma and sarcoma components that allowed the diagnosis of esophageal carcinosarcoma. Lymph node metastases and distant metastases were not observed. Discussion Tumor resection of the center and base of the protruding lesion with a wide margin allows an early and correct diagnosis of typical and atypical esophageal carcinosarcoma cases. Tumor resection with a wide margin can predict metastasis. Conclusions This rare case was correctly diagnosed during an early and asymptomatic stage.