Mature mediastinal teratoma with adhesions to the pericardium: A rare case report.

Key Clinical Message: Mature mediastinal teratoma (MMT) is a benign tumor that is composed of well-differentiated tissues from all three germ cell layers. Malignant tumors have a distinct feature of adhering to the surrounding organs. Therefore, adhesion of MMT to the adjacent tissues, as a benign tumor, is rare and considered a surgical challenge. It leads to incomplete tumor resection to avoid damage to the surrounding tissues.

Abstract: MMT is a germ cell tumor that contains well-differentiated tissues from ectodermal, mesodermal, and endodermal germ cell layers. MMT comprises approximately 3%-12% of mediastinal tumors in adults and 60%-70% of mediastinal germ cell tumors. Complete surgical resection is the standard treatment. When adhesion to the surrounding tissues is present, residual tissues could be retained to reduce the injury of the peripheral blood vessels and nerves. We are reporting a rare case of MMT with adhesions to the pericardium and discussing the diagnostic and surgical challenges.