title: Thymic carcinoma with myasthenia gravis: Two case reports.
abstract: BACKGROUND
  Myasthenia gravis (MG) has been reported to correlate with earlier-stage thymoma, and theoretically does not accompany thymic carcinoma. However, we encountered two cases of thymic carcinoma with MG.
  
  
  METHODS
  Case 1 involved a 54-year-old man who had been diagnosed with MG based on symptoms and detection of anti-acetylcholine receptor antibody (ARAB). Computed tomography (CT) revealed an anterior mediastinal tumor 30mm in diameter. Prednisolone (PSL) and tacrolimus were administered without surgery at that time. Six years after diagnosis of MG, he was admitted to our hospital and underwent extended thymectomy. Pathological examination revealed type B2-B3 thymoma according to World Health Organization criteria, comprising 80% of the tumor with small cell carcinoma as 20%. Case 2 involved a 51-year-old woman. She had been diagnosed with MG based on eyelid ptosis and detection of ARAB. Ten years after diagnosis of MG, diaphragm elevation was detected on chest X-ray. CT revealed an anterior mediastinal tumor, 47mm in diameter. We suspected tumor invasion to the right phrenic nerve, right atrium, and superior vena cava. We therefore performed extended thymectomy after preoperative radiotherapy (40Gy). Pathological examination revealed squamous cell carcinoma.
  
  
  CONCLUSIONS
  Most cases of thymic carcinomas appear to arise de novo, but appearance in thymomas has been described. In both our cases, MG was treated with pharmacotherapy alone without extended thymectomy, and thymic carcinoma was considered to have developed from the thymoma during long-term follow-up.
  
  
  CONCLUSIONS
  Thymic carcinoma can accompany MG.
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan. Electronic address: kurihara@gipc.akita-u.ac.jp.
authors: Nobuyasu
authors: N
authors: Kurihara
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Hajime
authors: H
authors: Saito
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Hiroshi
authors: H
authors: Nanjo
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Hayato
authors: H
authors: Konno
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Maiko
authors: M
authors: Atari
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Yoshitaro
authors: Y
authors: Saito
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Satoshi
authors: S
authors: Fujishima
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Komei
authors: K
authors: Kameyama
authors: Department of Thoracic Surgery, Akita University Graduate School of Medicine, Akita, Japan.
authors: Yoshihiro
authors: Y
authors: Minamiya
keywords: Myasthenia gravis,; Thymectomy; Thymic carcinoma; Thymoma