Abstract
A diaphragmatic tumor is usually caused by metastasis from lung cancer, malignant mesothelioma, and malignant thymoma. Endometrial cancer is rarely involved in metastasis to the diaphragm. A right anterior mediastinal tumor was found in a 60-year-old woman who was initially diagnosed with endometrial carcinoma. There was initially no relationship between the right anterior mediastinal tumor and endometrial carcinoma. Radical curative surgery was performed for endometrial carcinoma. The endometrial carcinoma stage was IA. The patient was admitted to the Department of Thoracic Surgery 6 months after the curative surgery. Intraoperative exploration showed a tumor growing in the right diaphragm. Right diaphragmotomy was performed. Immunohistochemistry showed metastasis of endometrial carcinoma to the diaphragm. Endometrial cancer solitary metastasis to the diaphragm is rare. Clinicians should be aware of this possibility. Surgical treatment followed by a pathological examination is the most useful method for determining the diagnosis of a diaphragmatic tumor due to metastasis of endometrial cancer.