[Myasthenia and Basedow's hyperthyroidism]

The authors report an exceptional case of myasthenia gravis associated with Graves' disease. Myasthenia gravis appeared at age 8 years. Hyperthyroidism was diagnosed at age 12 1/2 and quickly worsened, with signs of cardiothyrotoxicosis. In addition to the diagnostic difficulties, the immunologic origin seems to be implicated in these diseases. Thymectomy associated with subtotal thyroidectomy was performed, with good results during an 18 months follow-up.