Azygos vein aneurysm as a diagnostic pitfall. The role of thoracoscopy.

We report the case of an azygos vein aneurysm that was found intraoperatively in a 66-year-old woman followed for esophageal carcinoma. She underwent video-assisted thoracoscopy surgery (VATS) for biopsy of a mediastinal mass. This mass was diagnosed in the 2nd year of postoperative follow-up for a T2N0M0 esophageal carcinoma by computed tomography, which revealed a heterogeneous mass of ~2 cm in diameter in a retrotracheal location. Preoperative echoendoscopy demonstrated an extraesophageal lesion. A diagnostic thoracoscopy was done in order to exclude a metastatic lymph node disease.