Paraganglioma with ganglioneuromatous component located in the posterior mediastinum.

A 4-cm paravertebral mediastinal tumor was resected in a 70-year-old male patient treated for hypertension. The tumor displayed both paraganglioma and ganglioneuroma areas that were in equal proportion and often merged one into the other. Paraganglioma areas contained synaptophysin and chromogranin-positive chief cells and PS100-positive sustentacular cells. Ganglioneuroma areas contained neurofilament-positive mature ganglion cells and PS100-positive Schwann cells. Such pheochromocytoma-ganglioneuroma has not been previously reported in the mediastinum and appears as the adrenal and aorticosympathetic counterpart of gangliocytic paraganglioma described in other anatomic sites.