Ectopic pancreas in the anterior mediastinum.

We report an uncommon clinical case of anterior mediastinal localization of ectopic pancreatic tissue. A 39-year-old male was referred to our institution for investigation of an abnormal mediastinal shadow on a chest X-ray, and a large cystic lesion measuring 10 x 8 cm located in the anterior mediastinum was observed on a computed tomographic scan. He underwent complete surgical resection of the lesion. The postoperative pathological examination confirmed the diagnosis of ectopic mediastinal pancreas. No recurrence or metastasis was detected during a follow-up period of 8 years. We speculate that this lesion represents abnormal differentiation of the pluripotent epithelial cells of the ventral primary foregut. Details of the clinical and histopathological features are presented.