title: Thymoma patients with pleural dissemination: nationwide retrospective study of 136 cases in Japan.
abstract: BACKGROUND
  Thymoma is a rare mediastinal tumor with relatively slow growth. However, advanced-stage cases with pleural dissemination are occasionally encountered. The outcome of surgical resection for thymomas with pleural dissemination has not been clearly determined.
  
  
  METHODS
  We retrospectively investigated the clinical records of 2,835 patients with thymic epithelial tumors that were treated from 1991 to 2010 in 32 institutions that participated in the Japanese Association for Research on the Thymus. In this study, we analyzed the clinicopathologic factors and prognosis of thymoma patients with pleural dissemination who underwent surgical resection.
  
  
  RESULTS
  The thymomas with pleural disseminations numbered 148 cases (5.2% in the 2,835 thymic epithelial tumors). Surgical resection was performed in 136 cases. Pathologic Masaoka stages were classified as IVA (n=118) and IVB (n=18). In Masaoka stage IVA disease, the small number of disseminated pleural nodules (10 or fewer) was related to the curative resection. The prognosis was also better in these cases than in those with greater than 10 disseminated pleural nodules (certified during the operation; p=0.0057). Patients who underwent macroscopic total resection of disseminated nodules had a better prognosis than those with residual tumors (p=0.037). In stage IVA cases with complete resection (n=42), the efficacy of adjuvant chemotherapy, radiotherapy, or both was not demonstrated.
  
  
  CONCLUSIONS
  Macroscopic total resection of tumors appears to be a promising prognostic factor in Masaoka stage IVA thymomas. The number of disseminated pleural nodules correlated with resectability.
authors.affiliation: Department of Oncology, Immunology and Surgery, Nagoya City University Graduate School of Medical Science, Nagoya, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Okuda
authors.affiliation: Department of Oncology, Immunology and Surgery, Nagoya City University Graduate School of Medical Science, Nagoya, Japan. Electronic address: motoki@med.nagoya-cu.ac.jp.
authors.forename: Motoki
authors.initials: M
authors.lastname: Yano
authors.affiliation: Department of General Thoracic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yoshino
authors.affiliation: Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Japan.
authors.forename: Meinoshin
authors.initials: M
authors.lastname: Okumura
authors.affiliation: Department of Thoracic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Higashiyama
authors.affiliation: Division of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Tsuchida
authors.affiliation: Department of Thoracic Surgery, Nippon Medical School, Tokyo, Japan.
authors.forename: Jitsuo
authors.initials: J
authors.lastname: Usuda
authors.affiliation: Department of pathology, Kasugai Municipal Hospital, Kasugai, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tateyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D009375:Neoplasms, Glandular and Epithelial / Q000401:mortality / Q000556:secondary / Q000628:therapy; D010997:Pleural Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D035583:Rare Diseases; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D013934:Thymectomy / Q000379:methods* / Q000401:mortality; D013945:Thymoma / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D013953:Thymus Neoplasms / Q000401:mortality / Q000473:pathology / Q000556:secondary / Q000628:therapy*; D016896:Treatment Outcome; D055815:Young Adult