Abstract
The patient was a 51-year-old female. The chief complaint was atypical genital bleeding. Pelvic CT showed a tumor in the pelvis, and thoracic CT showed a posterior mediastinal tumor. She was recferred to gynecological and thoracic surgery departments for further examination. The preoperative diagnosis was a mature teratoma of the ovary and benign posterior mediastinal cyst. The patient underwent posterior mediastinal tumor resection following laparoscopic simple total hysterectomy and bilateral adnexotomy for the ovarian tumor. The mediastinal tumor had a thin wall and showed no adhesion to surrounding tissue. Pathological examination showed a mature teratoma of the ovary and a posterior mediastinal mullerian cyst, in which estrogen and progesterone receptors were positive on immunohistoligical examination. A Mullerian cyst in the posterior mediastinum is a new category of mediastinal cyst, initially reported by Hattori et al. in 2005. It occurs in perimenopusal females, especially in those with obesity or a gynecological history, but preoperative definitive diagnosis is difficult.
