Prognostic significance of thymomas in patients with myasthenia gravis.
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.
de Perrot
Marc
M
Division of Thoracic Surgery, Toronto General Hospital, Ontario, Canada.
Liu
Jiang
J
Bril
Vera
V
McRae
Karen
K
Bezjak
Andrea
A
Keshavjee
Shaf H
SH
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*