Posterior mediastinal cyst.

Hydatid disease is still an important health problem in the world. Mediastinal localization of hydatidosis is very rare. We report the case of a 19-year-old man who presented with right chest wall pain and cough. Chest X-Ray and computed tomography showed a mediastinal cystic mass. A right posterolateral thoracotomy was performed and the cystic mass was identified. Daughter cysts were seen within the cyst when the lesion was accidentally opened during the procedure. Cyst mass was radically resected. No complication or recurrence was seen in the follow-up period.