Asymptomatic but functional paraganglioma of the posterior mediastinum.

A 72-year-old woman was referred to our hospital because of a posterior mediastinal tumor. On the basis of detailed imaging tests, including (123)I-metaiodobenzylguanidine single photon emission computed tomography-computed tomography, and elevated values of catecholamines in the plasma and urine, the tumor was diagnosed as a functional mediastinal paraganglioma even in the absence of symptoms. After preoperative blood pressure control, surgical resection was performed. During the operation, the systemic blood pressure increased transiently as a result of surgical manipulation of the tumor. Soon after the tumor was removed, the patient conversely experienced hypotension. The postoperative course was uneventful, and pathologic diagnosis revealed a paraganglioma.