Endocrine Abstracts

Introduction: The ectopic ACTH syndrome accounts for 12% of patients with Cushing’s syndrome. Its diagnosis and treatment remains a challenge. This especially true in patients with ectopic ACTH production.

Case: We report the case of a 41-year-old man who presented with progressive muscle weakness in his arms and legs. He was found to be borderline hypertensive BP 145/92, cushingoid plethoric rounded face and mild proximal muscular weakness. His initial investigations revealed high serum cortisol of 931 and low K 3.4.

Further investigations revealed very high urinary free cortisol excretion 2454 and high urinary cortisol 944. Cortisol failed to suppress on both low dose and high dose dexamethasone tests 835 and 621 respectively. MRI pituitary with contrast (dynamic) shows a small area of non-enhancement at the base of pituitary stalk. The pituitary fossa itself was normal. IPSS failed to show a definite gradient and was equivocal (19 on the left, 22 on the right, 17 peripherally), and after CRH administrated there was no discernable rise. CT chest and abdomen revealed no ectopic source of ACTH. His Octreotide scan was also normal with no evidence of abnormal uptake.

He became more symptomatic especially with regards to his proximal myopathy. He was then started on metyrapone. However, he was not able to tolerate metyrapone and it was stopped. Pituitary surgery was not considered as his MRI findings were not entirely convincing.

Discussion: Difficulties encountering in the investigations of his Cushing’s syndrome. Would we consider alternative medical therapy? And if after exhaustive investigation, we failed to find a source of the ACTH, then bilateral adrenalectomy could be considered!