Thymectomy in the Treatment of Myasthenia Gravis

¹ Department of Surgery, The Lahey Clinic, Boston, Massachusetts.
² Department of Internal Medicine, The Lahey Clinic, Boston, Mass.

Thymectomy has been undertaken in an effort to alter the unfavorable course of myasthenia gravis in selected cases.

The incidence of thymic abnormalities found in autopsies of patients dying of myasthenia gravis is approximately 50 per cent. Aside from tumor, similar thymic abnormalities are found in other debilitating diseases. The incidence of myasthenia gravis in patients with benign thymoma is almost 100 per cent. Myasthenia gravis is very rare in association with malignant thymoma.

In our 8 cases there were 2 considerably improved, 4 moderately improved, 1 only slightly improved, and 1 death three days postoperatively. The results In 129 cases reported by six authors including our own cases, are 68 ( 52 per cent) classified as well, considerably or moderately improved after operation.

In view of the variation in the behavior of the disease and the lack of uniformity of results of thymectomy, operation is indicated only under the special circumstances which have been discussed.