Müllerian cyst in posterior mediastinum: A report of a case.

Introduction: A Müllerian cyst is a recently defined rare benign tumor of the posterior mediastinum. It is necessary to distinguish it from neurogenic tumor or bronchogenic cyst arising in the posterior mediastinum. Herein, we have reported and reviewed a case of Müllerian cyst in the light of the existing literature.

Presentation Of A Case: A 40-year-old woman was referred to our department for abnormal mediastinal tumor on computed tomography (CT). Chest CT revealed a 2-cm nodule in the left posterior mediastinum, while magnetic resonance imaging (MRI) T2-weighted scan revealed an elliptical, homogenous, and high-intensity neoplasm, and bronchogenic cyst or neurogenic tumor was suspected. She did not present with any symptoms. A thoracoscopic surgery was performed for the cyst removal. Histopathological examination revealed that the cyst wall was covered with a layer of columnar epithelium.　Immunohistochemical staining revealed the presence of estrogen receptor (ER) and progesterone receptor (PgR). Therefore a diagnosis of mediastinal Müllerian cyst was made.

Discussion And Conclusion: It is important to differentiate Müllerian cyst in the posterior mediastinal from other mediastinal cystic tumor for optimal decision-making in treatment.