Endocrine Abstracts

Introduction: Cushing’s disease (CD) is very rare in children and is invariably caused by a corticotroph adenoma. However, corticotroph cell hyperplasia has only been convincingly shown in two previous cases of paediatric Cushing’s disease. We report the case of a 7-year-old boy with Cushing’s disease caused by coticotroph cell hyperplasia.

Case report: Our patient presented with a 10-month history of obesity, hirsutism and growth retardation. His height was 2.5S.D. below the mean and his weight was over 98th percentile for age. Examination revealed a cushingoid facies, central obesity, striae and hirsutism. Biochemical assessment showed raised 24-h urine free cortisol and mid-night salivary cortisol with failure to suppress serum cortisol following low dose dexamethasone. Baseline 0900 h ACTH level was elevated. A peripheral CRH test showed a brisk rise in ACTH and cortisol consistent with Cushing’s disease. Pituitary MRI was normal. Bilateral inferior petrosal sinus sampling with CRH stimulation showed a central-peripheral gradient >3:1 at 10-min post-CRF confirming the diagnosis of pituitary dependent Cushing’s. The patient underwent endoscopic transphenoidal pituitary exploration. Abnormal tissue was resected from the left side of the pituitary. Histopathology revealed no adenoma but intense immunostaining for ACTH consistent with corticotroph hyperplasia. On the fourth post-operative day, am serum cortisol level was 39 nmol/l indicating early remission. Three months post-operatively he remained hypocortisolaemic on hydrocortisone with significant clinical improvement.

Conclusion: This case illustrates that paediatric Cushing’ disease may be caused, albeit very rarely, by cortricotroph hyperplasia. Careful follow-up in necessary as the recurrence rate of this entity is not known.