Mediastinal tumors are masses in the mediastianum that are rare, but have various histopathological types. Immunohistochemistry (IHC) is necessary to diagnose the type of mediastinal tumors. Here in Indonesia, especially in Riau Province, there is lack of literature regarding mediastinal tumors and IHC for these tumors. This study aims to obtain the IHC profile of mediastinal tumor patients in …