Abstract
We report a 72-year-old female who was hospitalized due to a cough and hemoptysis. Chest CT scan on admission revealed a mass in the anterior mediastinum. CT guided percutaneous aspiration cytology demonstrated debritic fluid. Microscopically, degenerated substances and partially degenerated ciliated columnar epithelial cells were recognized. Therefore we suspected that this mass was a thymic cyst lined by ciliated columnar epithelium. A median sternotomy was performed. Macroscopic appearance of the resected specimen demonstrated a monolocular thymic cyst with thymus and fatty tissues. The content was debritic fluid. Microscopic appearance showed a monolocular thymic cyst of which the wall was surrounded by thymus and fatty tissues. The cystic wall was lined by ciliated columnar epithelium. Incidental thymoma was not recognized. From these findings, this case was diagnosed as a thymic cyst of which the wall was lined by ciliated columnar epithelium.
Congenital thymic cysts are rare, and preoperative diagnosis is sometimes difficult. But in this case, as a result of percutaneous aspiration cytology, we were able to identify the epithelial cells, and diagnose this case as a congenital thymic cyst.
