[Long-term prognostic analysis of surgical treatment of the thymoma-associated myasthenia gravis].

Treatment results of 300 patients with myasthenia gravis (MG) were analyzed. 150 patients with MG and thymoma formed the main group, the rest 150 patients with non-thymomatous MG comprised the group of control. Thymomatous myasthenia was more severe and resistant to therapy. 79 (48.7%) patients had thymoma type B, mixed thymoma type AB was found in 45 (30.0%) patients, the rest had medullary tumors type A. I stage of the tumor progression was registered in 62.0% of cases, stage III was the second to find among them (20.0%). Long-term follow-up revealed stable and statistically proved improvement of MG clinic in patients of the main group (p=0.013). Survival rate of patients with thymoma and MG were 91.2, 83.4 and 72.3% after 3-, 5- and 10 years, correspondingly. Survival rates for non-thymomatous MG were significantly higher: 96.0, 91.6 and 87.2% after 3-,5- and 10 years, correspondingly. Tumor characteristics showed no influence on MG course after the operation. As well, as for the patients of the control group, only severity of the disease was the significant factor for the MG prognosis. Oncological prognosis was defined by pathomorphological type of thymoma and its progression stage. Thymomthymectomy allowed not only tumor remission but also myasthenia course stabilization and improvement.