A CASE OF PRIMARY CYSTIC MEDIASTINAL HEMANGIOPERICYTOMA

We describe a 35-year-old man with a primary cystic mediastinal hemang iopericytoma who presented with the complaint of progressive dysphagia for 6 months. The computed tomography and magnetic resonance imaging findings revealed that a well-defined, fluid-filled mass (measuring ap proximately 10x10 cm) was located posterior to the heart and inferior to the carina of the bronchus. Tumor puncture showed translucent yello w fluid with normal concentrations of carcinoembryonic antigen, squamo us cell carcinoma-related antigen, and carbohydrate antigen 19-9 and a high concentration of carbohydrate antigen 125. After removal of the tumor, microscopic examination revealed a malignant hemangiopericytoma . To our knowledge, this is the first case of a primary mediastinal he mangiopericytoma with cystic formation. Moreover, we showed the specif ic biochemical findings of the cystic fluid that were useful for diffe rentiation from other cystic mediastinal tumors.