RT Journal Article SR Electronic T1 An unusual cyst of posterior mediastinum: Mullerian cyst JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P3504 VO 40 IS Suppl 56 A1 Mehmet Dakak A1 Baris M. Poyraz A1 Safak Bulut A1 Cihangir Dogu A1 Selçuk Bilgin YR 2012 UL http://erj.ersjournals.com/content/40/Suppl_56/P3504.abstract AB In this case, we report a newly categorized mediastinal cyst called Mullerian cyst, which was reported for the first time by Hattori et al in 2005. A 51-year-old female patient was admitted to our hospital with the complaint of dysphagia. T2- weighted chest magnetic resonance imaging (MRI) showed a cystic lesion attached to the vertebral column in the posterior mediastinum.The patient underwent right thoracotomy. The cyst was tightly attached to esophagus and corpus of the 5th thoracic vertebra. The intact cyst was freed from posterior mediastinum.It was lined by a ciliated tubal-type epithelium and had a thin wall composed of smooth muscle. The epithelium showed estrogen and progesterone receptor expressions immunohistochemically. Mullerian cysts arise from remnants of the Mullerian duct and can be located anywhere along the path of Mullerian duct regression. Pelvis is the most common localization and their occurrence in the mediastinum is extremely rare. However mediastinal mullerian cyst is newly known entity, it should be kept in mind for the differential diagnosis of posterior mediastinal cysts.