Abstract: Objective To investigate the clinical characteristics of thymoma and thymoma with myasthenia gravis(MG). Methods From Oct.1979 to July 2004,185 patients with thymoma were surgically treated. Among these patients, comparative analysis was made between 94 cases of thymoma (thymoma group) and 91 cases of thymus tumor with MG(thymoma with MG group).155 patients underwent radical operation (83.8%),16 patients underwent palliative operation (8.6%),and 14 patients underwent exploratory operation (7.6%). Clinical characteristics was analyzed in two groups. The factors affecting prognosis was analyzed by Masaoka’s stage system, with the lifttable method. Results Five patients died after operation, others had complete remission or symptomatic improvement. There was statistically difference of Masaoka’s stage system in two groups (χ2=53.14, P＜0.05). There were no statistically difference in pathological type of thymoma and clinical type of MG and pathologic period (χ2=8.21, P＞0.05). 57 cases of thymoma group were followed up, the duration of follow-up was 1 to 10 years, average follow-up was 40.7 months, and the patients with 1-, 3- and 5-year survival rates were 70.2% (40/57), 66.7% (22/33), 593% (16/27) respectively. 55 cases of thymoma with MG group were followed up. The patients’ survival rates were 98.2% (54/55), 86.4% (38/44), 81.6% (31/38) at 1-, 3-and 5-year respectively. There was no statistically difference of survival rates in two groups (χ2=0.83, P＞0.05). Totally, 112 patients were followed up in two groups, by Masaoka’s stage system, the 5-year survival rates were 93.7% for stage Ⅰ, 79.2% for stageⅡ, 51.4% for stage Ⅲ and 0% for stage Ⅳ respectively. Result of asaoka’s stage system evidence was statistically significant (χ25-year=51.62, P＜0.01). Conclusions Pathological type of thymoma isn’t related to modified Osserman’s classification, prognosis of thymoma is obviously related to Masaoka’s stage and isn’t related to MG. Generalized MG is the major type in MG patients accompanied by thymomas, and the major pathological type is lymphocytic. Chest CT can increase the accuracy early diagnosis of thymoma. The principal treatment is to resect the tumor as completely as possible, and proper administration of postoperative radiotherapy or chemotherapy according to the surgical status. Operative program and tumor stage are the most important prognostic factors.
Objective To evaluate the risk factors affecting the prognosis in patients with myasthenia gravis after thymeetomy. Methods Therapeutic effects were evaluated with Relative Counting Method in 136 cases with myasthenia gravis who receivingthymectomy. Six clinical factors including sex, age, preoperative course, et al. were converted into quantitative parameters and used for analysis. Cumulative logit model for ordinal response was employed to investigate the therapeutic effects of various factors. Results Sex, age and preoperative course exerted significant effects on postoperative prognosis in patients with myasthenia gravis, while clinical subtype, pathological changes and preoperative administration of cholinesterase inhibitors had no significant impact on therapeutic effects. Conclusion Some factors may lead to the remission and improvement in postoperative patients with myasthenia gravis, therefore, they should be included for the evaluation of prognosis. Early diagnosis and early thymeetomy may improve the therapeutic effects and shorten the duration of amelioration.