Cushing's syndromemedical dictionary

<syndrome>

<endocrinology> An increased concentration of glucocorticoid hormone (ACTH) in the bloodstream that is being produced by an adrenal gland tumour (adenoma). Ectopic Cushing syndrome refers to the production of ACTH in a location other than the pituitary gland or adrenal gland.

Examples of ectopic sites include thymoma, medullary carcinoma of the thyroid, pheochromocytoma, islet cell tumours of the pancreas and oat cell carcinoma of the lung.

Symptoms include: weight gain, central obesity, moon face, weakness, fatigue, backache, headache, increased thirst, increased urination, impotence, mental status changes and muscle atrophy.

Treatment varies with cause. If an ACTH secreting tumour is involved then it must be removed surgically.

Causes: hyperplasia 70%, pituitary 90%, ectopic 10%, adrenal adenoma 20%, carcinoma 10%.

Clinical signs: retarded bone maturation, osteoporosis (most often axial), excess callus formation, stippled calvarium, demineralised dorsum sellae, CT: normal-sized adrenals in 1/3 of adrenal hyperplasia.

(11 Feb 2009)