[A case of thymic cyst and thymoma with myasthenia gravis].

A case of 53-year-old male with thymic cyst was reported. We established diagnosis for myasthenia gravis. The chest CT and MRI demonstrated a cystic and mass lesion on the anterosuperior mediastinum. This finding suggested a thymic cyst and tumor with myasthenia gravis. The extended thymectomy was performed. Histological examination demonstrated the clear separation of the mixed type thymoma and the thymic cyst. The few reported cases of thymic cyst and thymoma with myasthenia gravis were reviewed.