Systemic lupus erythematosus, pemphigus erythematosus, and thymoma in the same patient.

We describe a case of thymoma and pemphigus erythematosus developing in a 68-year-old woman 8 years after an initial diagnosis of systemic lupus erythematosus. Although numerous reports describe associations between any two of these entities, this case represents the first clearcut report of all three diseases in the same patient. The case description outlines the diagnostic approach to these diseases and reveals the importance of adhering to specific diagnostic criteria. Furthermore, by highlighting the potential role of thymic pathology in autoimmune disease, the case raises questions concerning pathogenesis of these disorders.