Endocrine Abstracts

Introduction: Complete long-term clinical remission in occult ectopic ACTH syndrome after a single adrenalectomy is unexpected.

Case report: 5 year ago, a 54-year-old man was admitted because of resistant HTA, multiple severe vertebral fractures, muscle weakness and cushingoid features of at least 1 year. Adrenal tests were diagnostic of ACTH-dependent Cushing’syndrome: ACTH=263 pg/ml, high plasma (62 μg/dl) and urinary free cortisol (UFC=1256 μg per day) with no suppression after both low-dose (cortisol=40.12 μg/dl; UFC=255.36 μg per day) and high-dose dexamethasone (cortisol=32.95 μg/dl; UFC=1193.2 μg per day). A pituitary MRI showed no identifiable tumour. CTs of the thorax and abdomen and a ¹⁸-FDG-PET CT scan failed to identify a possible tumour. A right adrenal laparoscopic adrenalectomy was performed. 1 mo postsurgery ACTH decreased to 79.8 pg/ml and cortisol was 16.7 μg/dl, non-suppressible with low dose DXM (7.37 μg/dl); low testosterone, 25OHD normalised, and bone turnover markers increased significantly (osteocalcin 10 ×). As clinical improvement was significant the patient declined the second adrenalectomy. 10 mo postsurgery all cushingoid features disappeared and the patient was in very good clinical condition with mild HTA and normal blood chemistries as he is now. Adrenal tests were performed annually: they fluctuated, with serum cortisol/UFC normal or high normal but nonsuppressible (or paradoxically increased); ACTH also was around 100 pg/ml. BMD increased progressively for 5 year (32% at the FN). 2 years ago a CT scan revealed a small pulmonary nodule (10 mm) but a SMS (¹¹¹-indium-pentetreotide) scan was negative; the nodule was stable on recent CT. We wait for the patient consent to operate the pulmonary nodule.

Conclusion: The case shows an unexpected rapid and complete clinical remission of a severe occult ectopic Cushing’ syndrome. The abnormal cortisol feed-back persisted for the duration of follow-up.