[A case of thymoma in an elderly patient associated with myasthenia gravis]

A case of thymoma in an elderly patient associated with myasthenia gravis (MG) was reported. A 81-year-old female with growing dim of eye was diagnosed as MG, and treated with Mestinon. Two months later, she was detected to have an anterior mediastinal tumor on chest rentogenography and CT. She was diagnosed as MG (Osserman type IIA) with thymoma by Tensilon test and high anti-acetylcholine-receptor antibody level. Extended thymothymectomy was performed and the tumor was encapsulated and not invasive (stage I, lymphocyte predominant type). Postoperative course was good and subjective symptoms were improved without medication.