Adenocarcinoma (somatic-type malignancy) in mature teratoma of anterior mediastinum.

Mature teratoma is a common anterior mediastinal tumour. However, occurrence of transformed malignant component within it is very rare. We report a case of a 32-year-old female presenting with dry cough and chest pain. Contrast-enhanced computed tomography (CT) showed a large thin-walled cystic lesion measuring 11.4 cm x 10.6 cm x 10.0 cm in the anterior mediastinum. Right postero-lateral thoracotomy was performed and the tumour was completely excised. Histopathological examination of the excised specimen was suggestive of mature teratoma with transformed malignant component, adenocarcinoma (somatic-type malignancy).