Intrapulmonary mature teratoma.

Intrapulmonary teratoma is reported in a 22-year-old male. A chest X-ray in a physical examination showed a round shadow in the left hilum of a 22-year-old man who, on admission, reported slight malaise and a decrease in body weight. Computed tomographic scan and magnetic resonance imaging of the chest showed a heterogeneously dense cystic lesion. The preoperative diagnosis was anterior mediastinal teratoma, and the tumor was located in the anterior segment of the left upper lobe after thoracotomy. Segmentectomy of the left upper division showed a 4.0 x 3.5 cm tumor diagnosed as an intrapulmonary mature teratoma--the 27th such case reported in the English-language literature. This is, to the best of our knowledge, the first intrapulmonary teratoma involving magnetic resonance imaging.