ESPE2024 Poster Category 2 Adrenals and HPA Axis (25 abstracts)
1Centre of Paediatrics and Adolescent Medicine, Division of Paediatric Endocrinology and Diabetology, University Hospital Freiburg, Freiburg, Germany. 2Childrens Hospital, Schwarzwald Baar Hospital, Villingen Schwenningen, Germany. 3Paediatric Endocrinology and Diabetology, Laboratory for Translational Hormone Analytics, Steroid Research & Mass Spectrometry Unit, Center of Child and Adolescent Medicine, Justus Liebig University, Giessen, Germany
Background: We present the case of a 7-year old girl presenting with undulant ACTH independent Cushing syndrome (CS).
Case presentation: The patient presented at a secondary care centre with hyperphagia, fatigue and 8 kg weight increase 4 weeks after an upper airway infection. The parents described a similar episode with spontaneous regression 12 months before. At physical examination she showed a cushingoid habitus with overweight (BMI 96th percentile), moon face and buffalo hump. ACTH was suppressed, serum cortisol was normal and 24h urinary cortisol was six-fold elevated. A 4 mg overnight dexamethasone suppression test showed no decrease in cortisol levels, confirming the diagnosis of an ACTH-independent CS. Adrenal sonography and MRI showed slender adrenal glands with no evidence of adrenal masses. The patient was referred to our tertiary care centre. ACTH was still suppressed, basal cortisol within the normal range, but without circadian suppression at night. 24-hour urinary cortisol was in the low range of normal, showing a cyclic course of the disease. We performed a high dose dexamethasone test over 48h, which showed a paradoxical increase in serum and 24-hour urinary cortisol metabolites excretion rate. Adrenal glands were normal also at multi-slice CT scan, raising the suspicion of micronodular adrenal hyperplasia. Genetic testing was performed, but no mutations in ARMC5, KDM1A, PDE11A, PDE88 or PRKAR1A genes were found. Treatment with the 11-beta hydroxylase inhibitor metyrapone was started to control hypercortisolism and hydrocortisone replacement was added after two days as a ‘block and replace’ therapy. At follow-up three weeks after discharge, 24-hour urinary steroidome analysis showed a cortisol metabolite excretion rate in the upper normal range and a 5-fold elevated 11-deoxycortisol metabolite excretion.
Conclusion: CS diagnosis can be challenging in patients presenting with undulant symptoms. The only definitive treatment (bilateral total adrenalectomy with lifelong complete adrenal insufficiency) should be considered only after failure of conservative treatment. Hydrocortisone replacement is of crucial importance in patients with suppressed HPA axis in order to avoid adrenal insufficiency.