Abnormalities of the thymus, including thymic tumors, have consistently been found in cases of myasthenia gravis since Weigert's observation in 1901.1 Reports have recently appeared associating thymoma with other clinical syndromes: acquired hypogammaglobulinemia,2 aregenerative anemia,3 and dermatomyositis.4 In this report are described two patients with thymoma and polymyositis who subsequently developed clinical myasthenia gravis. The findings in these cases and a review of the literature suggest certain relationships between polymyositis and myasthenia gravis and possibly between the disorders associated with thymoma.
Report of Cases
—A 61-year-old white housewife was admitted to The Mount Sinai Hospital in July, 1961, because of diffuse muscular weakness. Ten years previously an anterior mediastinal mass had been found on chest roentgenogram. The patient was then despondent over the deaths of two sisters from Hodgkin's disease, but was asymptomatic. No therapeutic measures were employed. Follow-up films demonstrated gradual enlargement of