Paradoxical response to dexamethasone in the diagnosis of primary pigmented nodular adrenocortical disease.
BACKGROUND
Primary pigmented nodular adrenocortical disease causes the Cushing syndrome in children and young adults and is most frequently associated with the Carney complex.


OBJECTIVE
To evaluate diagnostic tests for primary pigmented nodular adrenocortical disease.


METHODS
Retrospective cohort study.


METHODS
Tertiary care center.


METHODS
21 patients with primary pigmented nodular adrenocortical disease. The control groups consisted of 9 patients with macronodular adrenocortical disease and 15 patients with primary unilateral adrenocortical disease (single adenomas).


METHODS
Clinical characteristics, radiologic imaging, and a 6-day Liddle test with determination of urinary free cortisol and 17-hydroxycorticosteroid excretion.


RESULTS
Adrenal imaging and other tests were of limited value for the diagnosis of primary pigmented nodular adrenocortical disease. The Liddle test, however, distinguished patients with this disorder from those with other primary adrenocortical lesions. An increase of 50% or more in urinary free cortisol levels on day 6 of the Liddle test identified 9 of 13 patients (69.2% [95% CI, 46.6% to 91.8%]) with primary pigmented nodular adrenocortical disease, excluded all patients with macronodular adrenocortical disease, and was present in only 3 of the 15 patients with single adrenocortical adenomas (20% [CI, 0% to 40.2%]). An increase in urinary free cortisol excretion of 100% or more on day 6 of the Liddle test identified only patients with primary pigmented nodular adrenocortical disease.


CONCLUSIONS
Patients with primary pigmented nodular adrenocortical disease responded to dexamethasone with a paradoxical increase in glucocorticoid excretion during the Liddle test. This feature distinguishes such patients from those who have the Cushing syndrome caused by other primary adrenal disorders and may lead to timely detection of the Carney complex (a potentially fatal disorder) in asymptomatic patients.
Stratakis
C A
CA
National Institutes of Health, Bethesda, Maryland 20892-1862, USA. stratakc@ccl.nichd.nih.gov
Sarlis
N
N
Kirschner
L S
LS
Carney
J A
JA
Doppman
J L
JL
Nieman
L K
LK
Chrousos
G P
GP
Papanicolaou
D A
DA
D015065:17-Hydroxycorticosteroids / Q000652:urine; D000303:Adrenal Cortex Diseases / Q000175:diagnosis*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D015331:Cohort Studies; D003907:Dexamethasone; D005260:Female; D005938:Glucocorticoids; D006801:Humans; D006854:Hydrocortisone / Q000652:urine; D008297:Male; D010912:Pituitary-Adrenal Function Tests; D012372:ROC Curve; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
D015065:17-Hydroxycorticosteroids; D005938:Glucocorticoids; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone