Cystic lesions can be occasionally be found in the mediastinum, and typically include bronchogenic cysts, esophageal duplication cysts, and neuroenteric cysts. In 2005, Hattori described the first mediastinal cyst with Mullerian differentiation. Since that time, three other authors have described similar cysts occurring in the posterior mediastinum. Here we present two cases of patients with ciliated cysts with Mullerian differentiation with expression of estrogen receptor, progesterone receptor, PAX8 and Wilm's tumor 1, occurring in the posterior mediastinum and review the related literature.
Keywords: Mediastinal; estrogen receptor; mullerian cyst.