Disease Information for Cushing's disease/Syndrome: Definition

  • Cushing's Syndrome is a disease caused by an excess of cortisol production or by excessive use of cortisol or other similar steroid (glucocorticoid) hormones; Spontaneous overproduction of cortisol in the adrenals is divided into two groups - those due to an excess of ACTH and those that are independent of ACTH; A pituitary tumor producing too much ACTH, stimulating the adrenals to grow (hyperplasia) and to produce to much cortisol, is the most common type, and this is called Cushing's disease; It is the cause of 70% of spontaneous Cushing's syndrome; ACTH can also be produced outside the pituitary in a benign or malignant tumor in the lung, thymus gland, pancreas, or other organ; This is called "ectopic" ACTH production; When the source of excess cortisol production is a tumor of the adrenal gland itself, then it is not dependent on ACTH; The tumor makes cortisol on its own, and the other adrenal gland shrinks because ACTH production is suppressed; Adrenal cortex tumors can be benign (an adenoma), or malignant (a carcinoma) and are usually found on only one side; Pituitary Cushing's disease generally occurs after puberty with equal frequency in boys and girls; In adults, it has a greater frequency in women than men, with most found at age 25 to 45; Ectopic ACTH as a cause of Cushing's Syndrome is more common because of the high rate of lung cancer (about 660 per million per year), but it often goes unrecognized; The incidence increases with age; Both are also 4 to 5 times more common in women than men;

    Depending on the cause and duration of the Cushing's Syndrome, some people may have more dramatic changes, some might look more masculinized, some may have more blood pressure or weight changes; physical features include a tendency to gain weight, especially on the abdomen, face (moon face), neck and upper back (buffalo hump); thinning and weakness of the muscles of the upper arms and upper legs; thinning of the skin, with easy bruising and pink or purple stretch marks (striae) on the abdomen, thighs, breasts and shoulders; increased acne, facial hair growth, and scalp hair loss in women; sometimes a ruddy complexion on the face and neck; often a skin darkening (acanthosis) on the neck; Children will show obesity and poor growth in height; Adults find high blood pressure and evidence of muscle weakness in the upper arms and legs, and sometimes some enlargement of the clitoris in females; Symptoms usually include fatigue, weakness, depression, mood swings, increased thirst and urination, and lack of menstrual periods in women; Common findings on routine laboratory tests in people with Cushing's Syndrome include a higher white blood count, a high blood sugar (often into the diabetic range), and a low serum potassium; Ectopic Cushing's Syndrome tends to present with less impressive classic features, but more dramatic hypertension and loss of potassium; If untreated, Cushing's Syndrome will cause continued weakness of the muscles, fatigue, poor skin healing, weakening of the bones of the spine (osteoporosis), and increased susceptibility to some infections including pneumonia and TB;

    --------[Website MEDHELP_ORG Dr Paul Marguiles 2005]-------