[A case of adenocarcinoma of the thymus].

A case of adenocarcinoma of the thymus is reported in this paper. To the best of our knowledge, this is the first case of thymic adenocarcinoma in the world literature. A 51-year-old female was admitted to our hospital because of hyperthyroidism and anterior mediastinal tumor. After control of hyperthyroidism, thoracotomy was performed and the tumor was located in the right lobe of the thymus macroscopically. The tumor was extirpated and the specimen was revealed to be multiple thymic cyst with papillo-tubular adenocarcinoma proliferating in one of the cysts. The variability of the lining cells i.e. squamous, cuboidal, columnar, and transitional cell, suggest that the thymic cyst is of congenital origin and the adenacarcinoma is originated from multipotential lining cells of the cyst. She has no evidence of recurrence for 14 years postoperatively, therefore there is almost no possibility of metastasis from other organ to the anterior mediastinum.