ABSTRACT
Mediastinal teratoma is a rare mediastinal tumor. Patients with mediastinal teratoma are usually asymptomatic and are diagnosed incidentally with chest radiography or CT, but they may develop symptoms via a rupture into adjacent structures, which results in chemical pneumonia, massive hemoptysis, hemothorax, pericardial effusion, or respiratory distress. We report a case of a ruptured teratoma in a 31-year-old female presenting with cough and brown-colored sputum. Chest radiography and computed tomography of the chest showed an inhomogenous anterior mediastinal mass with fat and fluid component. It was successfully treated by surgical resection. Although mature teratomas are rare, we should be familiar with the unique CT features of a ruptured teratoma to make sure of a correct diagnosis.