Multilocular Thymic Cyst in a Young, Otherwise Healthy Woman: A Case Report.

Thymic cysts are rare lesions, accounting approximately for 1% of all mediastinal masses. We report a case of a 36-year old woman who presented preoperatively with a calcified mass shadow found on a routine chest radiograph X-ray. After further investigation with chest computed tomography (CT), magnetic resonance imaging (MRI), and tests for Myasthenia gravis, a benign mediastinal cyst was diagnosed and the patient underwent median sternotomy and complete surgical excision of the lesion. The histological examination described a multilocular thymic cyst. Thymic cysts are usually associated with thymic epithelial tumors, such as thymomas, or multisystemic morbid conditions such as human immunodeficiency virus (HIV) infection, rheumatologic disease, and Myasthenia gravis. At all follow-up examinations to date, the patient remains healthy.