The main rarity of our reported cases was the dynamic imaging findings very similar to the developmental process of tuberculosis in patients 1 and 2, the pachypleuritis in patients 2 and 3, the extremely elevated inflammatory markers very similar to empyema in patient 3, and the extremely atypical tumor shape in all patients. | Mediastinal teratoma presenting with hemoptysis and pleuritis misdiagnosed as tuberculosis (empyema)