BETWEEN 15% and 30% of patients with myasthenia gravis are said to have thymic tumors.1 However, roentgenographic delineation of thymomas is difficult because the x-ray shadow of the tumor often lies hidden within those cast by other mediastinal structures. Consequently, gas contrast methods such as pneumomediastinography have been used to outline mediastinal contents. However the technique is hazardous for seriously ill myasthenic patients and the results can be misleading. An atraumatic, rapid way to circumvent this difficulty may be radioisotopic scanning of the mediastinum with selenomethionine Se 75. The details of what may be a new method for detection of thymic tumors are summarized below.
Report of a Case
The patient (NCBH 43 02 80), a 63-year-old man, began to experience intermittent diplopia in September 1964. Over the ensuing months his double vision became constant and he gradually developed bilateral eyelid ptosis. Despite the use of near toxic doses