[Two Surgical Cases of Müllerian Cyst Arising From the Posterior Mediastinum].

We experienced 2 cases of Müllerian cyst. Case 1 was a 48-year-old woman with a paravertebral cystic tumor. The tumor grew from 23 to 31 mm in diameter for the 3 years. She underwent video-assisted thoracic surgery(VATS) for the excision of the tumor. Case 2 was a 40-year-old woman with a paravertebral cystic tumor, who underwent VATS. The Histological finding showed that the tumors of both cases were the cysts lined by non-stratified cuboidal to columnar epithelium and epithelial cells were positive in the nucleus with estrogen receptor immunohistochemically. The resected cysts were finally diagnosed as Müllerian cyst. Twenty four published cases of Müllerian cyst were reported before, including symptomatic and growing cases. There were some reports of malignant transformation in cases of pelvic origin.