Endocrine Abstracts

We present a 57-year-old female with Cushing’s syndrome characterised by new type 2 diabetes, hypertension, weight gain, bruising, proximal myopathy and depression. She also had poorly-healing cellulitic ulcers on both legs. Investigations: hypokalaemia and ACTH-dependent Cushing’s syndrome. Low dose dexamethasone suppression test: T=0 ACTH 85 ng/l, cortisol 907 nmol/l, T=48 h cortisol 807. High dose dexamethasone suppression test failed to suppress cortisol <50% baseline, with T=0 cortisol 1372 and T=48 h cortisol 825. MRI pituitary: left sided microadenoma. CT chest, abdomen and pelvis: no potential ectopic source of ACTH. In view of significant hypokalaemia, and failure to suppress cortisol during a HDDST, an ectopic ACTH source remained a differential diagnosis to Cushing’s disease. Inferior petrosal sinus sampling was not possible because she was too unwell: 1. Psychiatric problems: paranoia, agitation, obsessive-compulsive behaviour, anorexia and severe. 2. Sepsis (cellulitis and perforated sigmoid diverticulum): requiring laparatomy, which in turn was complicated by wound dehiscence. 3. Inadequate control of cortisol production despite maximal ketoconazole and metyrapone treatment, cortisol levels remained >1000 nmol/l. She needed continuous intravenous potassium replacement. We turned to subhyponotic etomidate administered on ITU. Initially this was successful in reducing serum cortisol to around 200 nmol/l but, within 2 weeks, her cortisol production escaped from etomidate control (5 mg/h). We added ketoconazole to the etomidate with still inadequate control of cortisol (approximately 500 nmol/l). Bilateral adrenalectomy as an emergency treatment was considered but it was felt that her previous peritonitis and impaired wound healing would jeopardize it’s success. It was decided to perform trans-sphenoidal hypophysectomy despite the lack of a definitive diagnosis. Histology confirmed a corticotroph adenoma. Serum cortisol level off hydrocortisone in the early post-operative period was 168 nmol/l. This case highlights the following points: A. The use of etomidate as an inhibitor of steroidogenesis, and its place in the management of Cushing’s syndrome. B. The timing of surgery for Cushing’s syndrome, in particular how long should biochemical control of hypercortisolism be maintained before surgery? C. The inaccuracy of the high dose dexamethasone suppression test.

Hypophysectomy despite the lack of a definitive diagnosis. Histology confirmed a corticotroph adenoma. Serum cortisol level off hydrocortisone in the early post-operative period was 168 nmol/l.

The presentation will discuss the following points:

A. The use of etomidate as an inhibitor of steroidogenesis, and its place in the management of Cushing’s syndrome.

B. The indication and timing of surgery for Cushing’s syndrome, in particular how long should biochemical control of hypercortisolism be maintained before surgery?

C. The Mental Capacity Act and how this legislation affects the management of ill patients with neuropsychiatric manifestations of Cushing’s syndrome.