A Case of a Müllerian Cyst Arising in the Posterior Mediastinum

Abstract

The patient was a 44-year-old woman in whom a mediastinal cyst was detected on chest radiography during a medical examination. A chest computed tomography (CT) showed a posterior mediastinal tumor. She was referred to our department of thoracic surgery. A preoperative diagnosis of benign posterior mediastinal cyst was established by using magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET-CT). The patient underwent thoracoscopic resection of the posterior mediastinal tumor. The mediastinal tumor was a monolocular cyst covered with a thin capsule and showed no adhesions to the surrounding tissue. Pathological examination showed a posterior mediastinal müllerian cyst, in which the cystic wall was composed of mono- or multi-layered low cylindrical ciliated epithelial cells and both estrogen and progesterone receptors were positive on immunohisto chemistry. Müllerian cyst was thus diagnosed. After the surgery, she got Horner signs that vanished 6 months later. When we encounter a posterior mediastinal cyst in perimenopausal women, mullerian cyst should be suspected.