[The treatment of thymoma with myasthenia gravis: report of 20 cases]

Sixty-eight patients with myasthenia gravis underwent thymic surgery in our department. Among of 68 cases, twenty patients with thymoma were followed and their prognosis were investigated. Sixteen cases received a extended thymectomy with thymomectomy, six cases received local irradiation, and 16 cases received a chemotherapy. Among of 16 cases, 13 cases received corticosteroid only, and 3 cases received CHOP (CPA+ADM+VCR+PSL). Survival rates for thymoma of 20 cases were 94.7%, 88.9%, 78.6%, and 54.5% at 1, 3, 5 and 7 years, respectively. Survival rates for thymoma at 5 years were 83.3%, 50.0%, 100%, and 100% in stage I (complete encapsulation of 8), II (invasion into pericapsular fatty tissue of 7), III (invasion into surrounding organ of 3), and IV a (pleural dissemination of 2), respectively. Survival rate for extended thymectomy with thymomectomy of 16 cases was 81.8% at 5 years. Among of 18 total resection cases of thymoma, a recurrence occurred (5.6%). Causes of 6 death after surgery were crises of myasthenia gravis (3), other diseases (2), and recurrence of thymoma (1).