Castleman's disease associated with follicular dendritic cell sarcoma and myasthenia gravis.

Castleman's disease is an atypical lymphoproliferative disorder of unknown etiology, which might be associated with various clinical conditions, including autoimmune diseases and malignant neoplasms. We report the case of a 72-year-old female patient who was referred to the thoracic surgery department of Getúlio Vargas University Hospital, in the city of Manaus, Brazil, for the resection of a posterior mediastinal tumor. Three months prior, the patient had been admitted to the ICU with signs of severe dyspnea, at which time she was diagnosed with myasthenia gravis.