With the availability of the newer techniques and advances in surgery and anesthesia, the modern surgeon has been called upon to operate on more and more groups of patients whose medical disease presents formidable operative risks. No single group of subjects exemplifies this better than the myasthenic patient undergoing thymectomy. While the indications and selections for the operative approach in myasthenia gravis are still being modified,1-4 these patients are being operated upon in an effort to increase patient salvage in the group with this syndrome. This controversy will not be presented here, but it is pertinent to mention that a certain proportion of the myasthenic population merits special consideration apart from the existence of their disorder. Recent data5 indicate that in the myasthenic patient with thymoma, this tumor has a far higher malignant potential than was previously reported. Castleman6 found an incidence of 25% malignancy in thymoma.