Cushing's syndrome due to an ACTH-secreting adrenal medullary tumour.

A 35-year-old man with Cushing's syndrome due to ectopic ACTH production is described. The six-week history and severe proximal myopathy were highly suggestive of a malignant tumour, but a solitary phaeochromocytoma of the left adrenal gland was the source of ACTH production. The surgical outcome was successful and three months post-operatively the hypothalamic-pituitary-adrenal axis was normal. At 12 months follow-up he remains well with complete regression of the features of Cushing's syndrome.