A relationship between the thymus and myasthenia gravis has been accepted by a number of investigators.* However, the nature of this association is still unknown. Nevertheless, in patients with myasthenia gravis whose disease cannot be adequately controlled with medication, irradiation or removal of the thymus has been recommended.† The results of surgery have been variable, but it is generally agreed that they are better in those patients who have a simple hyperplasia of the thymus than in those with a thymic tumor.
The appearance of myasthenia gravis after the removal of a thymoma is quite rare. A review of the literature has disclosed only four cases in which symptoms of myasthenia developed following excision of a thymoma.
Fershtand and Shaw 14 reported the onset of myasthenia gravis in a 27-year-old man who had a three-week history of chest pain and signs of superior vena caval obstruction. A mass extending along