Coexistence of systemic lupus erythematosus and myasthenia gravis

The coexistence of myasthenia gravis and systemic lupus erythematosus in a 52-year-old woman is reported. Review of the literature shows that systemic lupus erythematosus occurs much more often in the myasthenia gravis population than in the population in general. Myasthenia gravis should be considered in the differential diagnosis in a patient with weakness and systemic lupus erythematosus.