[Giant cell myositis and myasthenia gravis: a case report].

We report the case of a 63-year-old patient with muscular weakness in the context of a myasthenia gravis evolving for 4 years. Although myasthenia gravis was under control, aggravation of muscular weakness led to perform a muscular biopsy. It showed a giant cell myositis, which is usually described in sarcoidosis but can also be found in a context of myositis associated with myasthenia gravis.