title: Prognostic significance of thymomas in patients with myasthenia gravis.
abstract: BACKGROUND
  The presence of thymoma may be a negative prognostic factor with respect to the outcome of myasthenia gravis (MG).
  
  
  METHODS
  Of 122 consecutive patients with MG undergoing thymectomy between August 1994 and September 2000, 37 had a thymoma. Postoperative radiation was administered to all patients with stage II thymoma and higher. To determine differences in presentation and outcome, thymoma patients were compared with patients with atrophic (n = 49) or hyperplastic (n = 36) thymus gland on final pathology.
  
  
  RESULTS
  Thymoma patients were significantly older (52 +/- 14 vs 36 +/- 15 years, p < 0.0001) and included a significantly higher proportion of males (54% vs 28%, p = 0.006) than patients without thymoma. However, the preoperative Osserman grade and the duration of symptoms before surgery were not significantly different between groups. Mean follow-up after thymectomy was not significantly different between patients with or without thymoma (32 +/- 23 vs 37 +/- 19 months, respectively, p = 0.3). At last follow-up, the proportion of asymptomatic patients (63% vs 70%, respectively, p = 0.5) and the mean Osserman grade (0.6 +/- 0.9 vs 0.5 +/- 0.9, respectively, p = 0.6) were similar in both groups. In addition, the rate of complete remission reached 36% at 5 years in patients with or without thymoma (p = 0.8).
  
  
  CONCLUSIONS
  Although myasthenic patients with thymoma are significantly older and include a greater proportion of males, the overall outcome, including the rate of complete remission, was similar between patients with or without thymoma. Therefore, the presence of a thymoma should not necessarily be viewed as a negative prognostic factor regarding recovery from myasthenia gravis.
authors.affiliation: Division of Thoracic Surgery, Toronto General Hospital, Ontario, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: de Perrot
authors.forename: Jiang
authors.initials: J
authors.lastname: Liu
authors.forename: Vera
authors.initials: V
authors.lastname: Bril
authors.forename: Karen
authors.initials: K
authors.lastname: McRae
authors.forename: Andrea
authors.initials: A
authors.lastname: Bezjak
authors.forename: Shaf H
authors.initials: SH
authors.lastname: Keshavjee
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000175:diagnosis / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D009367:Neoplasm Staging; D009460:Neurologic Examination; D011183:Postoperative Complications / Q000175:diagnosis*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D013934:Thymectomy; D013945:Thymoma / Q000175:diagnosis / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D013953:Thymus Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*