title: Extrathymic malignancies associated with thymoma: a forty-year experience at a single institution.
abstract: Patients with thymoma are reported to have an increased risk for developing second malignancies. The aim of this study was to assess the incidence of second malignancies among patients with thymoma. We focused especially on the impact that lung cancer has on survival in these patients.
  
  
  
  Three hundred and thirty-five patients who underwent surgery for thymoma in Chiba University Hospital from January 1971 to November 2012 were included in this study. Patient records were reviewed retrospectively for data on background, treatment, second malignancies and clinical outcome.
  
  
  
  Fourteen patients had a history of malignancy until the time of operation, with an additional 20 diagnosed simultaneously with the thymoma. Forty-three malignant lesions in 33 patients were found post-thymectomy. Lung cancer was diagnosed in 17 patients, far exceeding the expected number in the cohort, which was calculated according to Japanese national data. The median survival time of the thymoma patients who had lung cancer at the time of surgery was 5.8 years. The survival of patients with thymoma and lung cancer was poor in comparison with that of others.
  
  
  
  Secondary lung cancer is frequently found in thymoma patients and could be one of the factors limiting survival. We recommend an annual computed tomographic scan of the thorax to detect not only recurrent thymoma but also lung cancer at an early stage in order to improve the survival of these patients.
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Kamata
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Wada
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Hidemi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Takekazu
authors.initials: T
authors.lastname: Iwata
authors.affiliation: Department of Diagnostic Pathology, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakatani
authors.affiliation: Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yoshino
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies; D015996:Survival Rate; D013934:Thymectomy; D013945:Thymoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D013953:Thymus Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery
keywords: Extrathymic malignancies; Lung cancer; Thymoma