title: Evaluation of the clonidine-suppression test in the diagnosis of pheochromocytoma.
abstract: In this study we examined the preoperative value of the clonidine-suppression test in 15 patients with surgically proved pheochromocytomas. The result of the clonidine-suppression test was pathological (epinephrine plus norepinephrine above 500 ng/l 3 h after clonidine) in 10 of 15 patients (66%). These patients had relatively large tumors and higher basal norepinephrine plasma levels. Out of the 5 cases without a pathological clonidine test 4 had normal basal plasma catecholamine levels with the result that the clonidine test could not be properly applied and 1 case produced a false negative result. These 5 cases generally had smaller tumors and lower plasma catecholamine levels. Two of these cases had basally raised epinephrine values. The other three cases had either a paradoxical increase or a suspiciously low fall (less than 25%) in norepinephrine within the normal range. We conclude that the clonidine-suppression test is only reliable for the diagnosis of relatively large pheochromocytomas.
authors.affiliation: Abteilung für Klinische Endokrinologie der Universität Mainz.
authors.forename: G
authors.initials: G
authors.lastname: Plewe
authors.forename: U
authors.initials: U
authors.lastname: Krause
authors.forename: U
authors.initials: U
authors.lastname: Cordes
authors.forename: J
authors.initials: J
authors.lastname: Beyer
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000097:blood / Q000175:diagnosis*; D000328:Adult; D003000:Clonidine; D004837:Epinephrine / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood*; D010673:Pheochromocytoma / Q000097:blood / Q000175:diagnosis*
chemical_list: D003000:Clonidine; D009638:Norepinephrine; D004837:Epinephrine