Metastatic thymoma to the peritoneum: A case report

Thymomas usually consist of mostly benign histology, yet their malignant potential and distant metastasis remains unpredictable. Extrathoracic distant metastasis of malignant thymomas to the peritoneum are rare and only two cases are noted in the literature. We report a third case of diffuse intraperitoneal metastasis from an epithelial cell-based thymoma of the mediastinum. Metastasis to the peritoneum occurred 312 years after the initial diagnosis. Our case is noted for its aggressive behavior and relatively short interval of distant metastasis to the peritoneum despite four different chemotherapeutic regimens and radiation therapy.