A 53-year-old female, who 5 years ago had undergone hysterectomy for microinvasive adenocarcinoma of the uterine cervix, presented with progressive dysphagia and weakness. She was diagnosed as having myasthenia gravis. CT scan showed a contrast enhancing mass in the anterior mediastinum, measuring 5 x 4.5 x 1.5 cm.
Thymectomy was performed and the specimen showed a solid mass with cystic foci.