Thymectomy in late-onset myasthenia gravis.

Two cases of late-onset myasthenia gravis were successfully treated by thymectomy using a sternal splitting technique, in spite of the fact that no thymomas could be detected preoperatively. One patient was seriously ill, the other patient responded to medical treatment. Thymolipoma and malignant thymoma, respectively, were removed from the patients. It is stressed that not all thymomas produce antibodies to striated muscles and that CT-scan of the mediastinum is of limited value in the diagnosis of thymoma. It is suggested that patients with late-onset myasthenia gravis be offered thymectomy, even in the absence of detectable thymomas.