ESPE Abstracts

Background: The overall incidence of Cushing’s syndrome in children is ~0.2–0.5 new cases per million people per year. Cushing’s disease is more infrequent under 7-year-old children. The typical symptoms are not often observed in childhood. Therefore, the early diagnosis is difficult, when pituitary tumour is not detected by pituitary MRI.

Objective and hypotheses: A 5-year-old boy was referred to our hospital by a decrease in growth velocity with obesity (Ht: 102.4 cm (−1.3S.D.), Wt: 24.4 kg (+2.1S.D.)). He has moon face, buffalo hump, hypertension, peripheral edema, and pigmentation.

Method: His 24-h urinary free cortisol was 76.2 μg/day, and 61.7 μg/day (referral range: <70 μg/m²) and basal ACTH level was 61.5 pg/ml (referral range: <10 pg/ml). In addition to his clinical symptoms, Cushing’s syndrome was suspected due to incomplete suppression of plasma cortisol levels with a low-dose overnight dexamethasone suppression test (DEX: 20 μg/kg, ACTH: 21.2 pg/ml, cortisol: 21.2 μg/dl). In the high-dose dexamethasone suppression test (DEX: 120 μg/kg), the cortisol level was suppressed (ACTH: 2.5 pg/ml, cortisol: 1.3 μg/dl). Despite of the results of endocrine test, enhanced pituitary MRI was no findings of adenoma. Then, we performed a selective sinus sampling test to confirm the over-secretion of ACTH from pituitary gland. He had 10.5-to-1 central (left inferior petrosal sinus)-to-peripheral gradient at baseline and 42.4-to-1 central-to-peripheral gradient after stimulation with CRH injection (CRH: 1.5 μg/kg) during the sinus sampling. Finally, he was diagnosed with Cushing’s disease.

Results: Routine pituitary imaging was reported to detect ACTH-secreting tumours in ~50%. Bilateral inferior petrosal sinus sampling should be considered in patients suspected of having Cushing’s features for earlier diagnosis and treatment.

Conclusion: We diagnosed 5-year-old patient with Cushing’s disease. This case was not detected with pituitary findings by MRI, but we must perform a selective sinus sampling test to diagnose Cushing’s disease even under 7-year-old.