A mediastinal Mullerian cyst was initially reported as a new category of congenital cyst by Hattori, et al. in 2005. We treated a 53-year-old female referred to us with a posterior mediastinal tumor found at the Th5 prevertebral level by chest-computed tomography during a medical check-up. She had a history of mediastinal teratoma, which was removed at the age of 35. Chest magnetic resonance imaging revealed homogenous, high-intensity signals in T2-weighted images. The lesion was resected using a thoracoscopic procedure, and histologic and immunohistochemical staining revealed a ciliated cyst of Mullerian origin. The newly established mediastinal Mullerian cyst should be included in the differential diagnosis of posterior mediastinal cysts.
2012 The Editorial Committee of Annals of Thoracic and Cardiovascular Surgery