[Management of myasthenia gravis (MG) associated with thymoma]

From June 1975 to June 1992, we experienced 203 patients with MG. Sixty patients had associated thymoma, registering stages I (n = 31), II (n = 18), III (n = 9), and IV a (n = 2), according to the classification of Masaoka and colleagues. Fifty patients had generalized MG and 10 had ocular MG. Histopathological findings indicated round-oval, polygonal cell type in 46 patients and mixture of round-oval and spindle cell type in 11 patients and invasive thymomas had a tendency to have a predominantly epithelial type with and increased epithelial element as compared with non-invasive thymomas. An extended thymectomy including thymoma was performed in all patients. Three patients in stage II, 7 patients in stage III, and 2 patients in IV a received postoperative radiation therapy. Twenty-one patients needed prolonged respiratory care for respiratory crisis. Fifty-three patients have been doing well with the alternate-day corticosteroid therapy, however, 4 patients had an excavation of myasthenic symptoms associated with recurrence of thymoma on the pleura. In conclusion, early extended thymectomy including thymoma is markedly effective therapy for MG with thymoma and a careful attention should be paid for recurrence in the patients with invasive thymoma.