Ruptured mediastinal teratoma mimicking a lung parenchyma lesion

A 28-year-old man presented with recurrent hemoptysis for 14 years. He had been informed that he had a mediastinal mass 6 years ago, but he had refused surgery. One month before this admission, he suffered from cough with profuse hemoptysis. Chest radiographs showed an irregular mass lesion in the perihilar region of the right upper lung, abutting the mediastinum. Chest CT scan revealed a 6.8-cm tumor mass with irregular tumor margins, involving the upper lobe of the right lung (RUL) and right anterior mediastinum. The mass had inhomogeneous density with fat density within the tumor. Histologic diagnosis was compatible with a ruptured mature teratoma of the anterior mediastinum with involvement of the RUL.