ESPE Abstracts

Background: Hypercortisolism due to PPNAD may be cyclical, atypical and may develop suddenly or progressively.

Objective and Hypotheses: The performance of salivary cortisol (SF) in this rare cause of Cushing’s syndrome (CS) is lacking.

Method: Ten patients (nine F/one M) with PPNAD (two sporadic; eight Carney complex) were evaluated. Among these, six had CS family history, while in two the diagnosis was confirmed by germline PRKAR1A mutation. Median age at CS diagnosis was 13.5 years (range 4–28). Seven patients presented overt CS, two developed symptoms during follow-up, and one still has no clinical CS. Saliva samples for cortisol assay (RIA) were collected at 0900 and 2300 h (LNSF) and after overnight 1-mg dexamethasone suppression test (DST). Baseline plasma ACTH and cortisol after DST were obtained. In three patients without CS at presentation, longitudinal LNSF were evaluated during 16 months to 5 years follow-up.

Results: Baseline LNSF of all patients (mean±S.D.) was 890±674 ng/dl. In 7/10 patients LNSF levels were above the cutoff level (≥350 ng/dl or 9.8 nmol/l). In three patients, there was a progressive increase of LNSF during longitudinal evaluation. After 1-mg DST, mean SF was 962±1149; all patients had SF above the cutoff level (>150 ng/dl or 4.2 nmol/l). Mean plasma cortisol after 1-mg DST was 17.4±12 μg/dl; all patients had values above the cutoff level (≥2.0 μg/dl or ≥55 nmol/l). Baseline plasma ACTH was 13.4±2.8 pg/ml (range<5–17), and undetectable ACTH was observed in 5/10 patients. Nine patients with overt CS underwent bilateral adrenalectomy; PPNAD was confirmed by histopathology.

Conclusion: Our data confirm that plasma or salivary cortisol after 1-mg DST are the most useful tools for the diagnosis of hypercortisolism in children and adults with sporadic or Carney complex PPNAD. Of note, LNSF may provide information on the temporal development of hypercortisolism in PPNAD. In addition, in PPNAD, normal ACTH levels do not exclude CS.