Posterior mediastinal Müllerian cyst in a patient with Mayer-Rokitansky-Küster-Hauser syndrome: a case report.

Posterior mediastinal cysts are rare lesions accounting for ~5%-10% of mediastinal cysts. Most are bronchogenic, enteric, or neurogenic in origin; however, Müllerian cysts have recently been recognized as a distinct entity thought to arise from displaced Müllerian duct tissue. Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome results from incomplete development of Müllerian ducts and is characterized by congenital absence of the uterus and upper vagina. A shared embryological origin suggests a possible association between MRKH syndrome and mediastinal Müllerian cysts. We report the first known case of a posterior mediastinal cyst in a patient with MRKH syndrome type II treated successfully with uniportal video-assisted thoracoscopic surgery. We discuss the clinical presentation, histopathological findings, surgical management, and potential embryological link between these conditions.