The role of desmopressin in bilateral and simultaneous inferior petrosal sinus sampling for differential diagnosis of ACTH-dependent Cushing's syndrome.
OBJECTIVE
Bilateral inferior petrosal sinus sampling (BIPSS) with corticotrophin-releasing hormone (CRH) stimulation is currently the gold standard test for the differential diagnosis of ACTH-dependent Cushing's syndrome. Reports on the use of desmopressin in this approach are limited. The aim of this study was to evaluate the use of desmopressin during BIPSS in a cohort of patients with ACTH-dependent Cushing's syndrome.


METHODS
A retrospective case-record study.


METHODS
Fifty-six patients with confirmed ACTH-dependent Cushing's syndrome underwent BIPSS with desmopressin stimulation when presenting negative pituitary tumour imaging.


METHODS
Central to peripheral (CEN:PER) ACTH gradient, lateralization of the ACTH source and surgical tumour confirmation were evaluated.


RESULTS
A CEN:PER ACTH gradient was found in 40 patients under basal conditions (CEN:PER >or= 2) and in 47 patients after desmopressin stimulation (CEN:PER >or= 3). Ectopic ACTH-producing tumours (three lung carcinoid tumour, one thymus carcinoid tumour and one thymus hyperplasia) were confirmed in five out of nine patients without the CEN:PER ACTH gradient, and four cases were false negative for Cushing's disease. Lateralization (IPS:IPS >or= 1.4) was observed in 80.8% of patients under basal conditions (38/47) and in 97.8% after desmopressin (46/47), and it was surgically confirmed in 78.7%. There were no false-positive cases. Sensitivity and specificity were 92.1% and 100%, respectively.


CONCLUSIONS
Desmopressin improves the differential diagnosis of ACTH-dependent Cushing's syndrome by amplifying the CEN:PER and IPS:IPS ACTH gradients, and is therefore a useful ACTH secretagogue in BIPSS.
Machado
Marcio Carlos
MC
Division of Endocrinology and Metabolism, University of Sao Paulo School of Medicine, Sao Paulo, SP, Brazil.
de Sa
Sandra Valeria
SV
Domenice
Sorahia
S
Fragoso
Maria Candida B Villares
MC
Puglia
Paulo
P
Pereira
Maria Adelaide Albergaria
MA
de Mendonça
Berenice Bilharinho
BB
Salgado
Luiz Roberto
LR
D000182:ACTH Syndrome, Ectopic / Q000097:blood / Q000175:diagnosis / Q000601:surgery; D000236:Adenoma / Q000097:blood / Q000175:diagnosis / Q000601:surgery; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D003480:Cushing Syndrome / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D003894:Deamino Arginine Vasopressin; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D017591:Petrosal Sinus Sampling / Q000379:methods*; D010911:Pituitary Neoplasms / Q000097:blood / Q000175:diagnosis / Q000601:surgery; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D013268:Stimulation, Chemical
D000324:Adrenocorticotropic Hormone; D003894:Deamino Arginine Vasopressin; D006854:Hydrocortisone