Dopamine in paragangliomas of the glomus jugulare.

Glomus jugulare tumors have the ability to synthesize, store, and secrete biogenic amines. Although the majority of these tumors remain endocrinologically silent, on rare occasions they present either as a pheochromocytoma or with a carcinoid syndrome. We report a 20-year-old male with two intracranial tumors: an intrasellar neoplasm and a glomus jugulare tumor. Catecholamine catabolites in the urine were not increased, and blood pressure was always normal. The pituitary tumor was an adenoma, immunostaining positive for prolactin. The second patient, a 29-year-old hypertensive male, with a glomus jugulare tumor, had increased vanillylmandelic-acid excretion. In both cases, the paraganglioma tumor cells contained numerous dense-core vesicles (125 to 380 nm in diameter) in electron microscopy, and showed intense fluorescence by the sucrose-potassium phosphate-glyoxylic acid method. Using high-performance liquid chromatography and microspectrofluorometry we were able to establish the presence of large amounts of dopamine in the cytoplasm of the tumor cells.