Table 1 Summary of dynamic tests
From: Paediatric cyclical Cushing’s disease due to corticotroph cell hyperplasia
Test | Result | Interpretation |
|---|---|---|
1 mg overnight DST | Morning cortisol 258 nmol/L | Failure to suppress cortisol secretion |
(normal suppression < 50 nmol/L) | ||
24 h UFC | 987 nmol/L | Values greater than 3 times ULN are highly suggestive of Cushing’s syndrome |
(Ref. 0–83 nmol/L) | ||
CRH test | ACTH 0 mins 60 pg/ml | Greater than 50 % rise in ACTH, suggestive of Cushing’s syndrome |
Cortisol 0 mins 756 nmol/L | ||
ACTH 15 mins 104 pg/ml | ||
Cortisol 15 mins 1126 nmol/L | ||
IPSS (CRH augmented) | ACTH values 5 mins post CRH | No central to peripheral gradient |
Left petrosal 166 pg/ml | ||
Right petrosal 92 pg/ml | ||
peripheral 77 pg/ml | ||
IPSS (CRH augmented) | ACTH values 5 mins post CRH | Marked central to peripheral gradient (PPV 98 %) |
Left petrosal >2100 pg/ml | ||
Right petrosal 271 pg/ml | ||
peripheral 176 pg/ml |