38
The
th Annual Meeting of April 8-9, 2017 The Endocrine Society and The Diabetes Association of the R.O.C. (Taiwan)
SE1-1
CUSHING’S SYNDROME: UPDATE AND REVIEW ചో ᇄіᄹҖᖃᚃଲϲऌഌϲϸݫᄳུചхᗃऌ
&XVKLQJ¶V V\QGURPH ¿UVW GHVFULEHG E\ +DUYH\ &XVKLQJ LQ DQG LV D JURXS RI GLVHDVHV due to prolonged exposure to cortisol. Signs and symptoms may include abdominal obesity with thin arms and legs, a round red face, a fat lump between the shoulders, purplish stretch marks (striae), acne, fragile skin with heals poorly, muscles weakness, osteoporosis and high blood pressure. Women may have more hair and irregular menstruation. Occasionally there may be changes in mood, headaches, and a chronic feeling of tiredness. Cushing’s syndrome is generally considered a rare disease. It occurs an incidence of 0·2–5·0 per million people per year with a prevalence of 39–79 per million in various populations. However, a mild degree of overproduction of cortisol without obvious symptoms is more common. Endogenous Cushing’s syndrome is divided between ACTH-dependent (about 80%) and ACTH-independent (about 20%) causes. Among ACTH-dependent forms, pituitary corticotroph adenoma (Cushing’s disease) is the most common, followed by ectopic ACTH syndrome, and CRH syndrome is rare. Cortisol excess from primary unilateral adrenal adenomas or carcinomas suppresses ACTH. Rarely, Cushing’s syndrome is caused by primary bilateral macronodular adrenal hyperplasia (BMAH), ACTHindependent macronodular adrenal hyperplasia (AIMAH) or primary pigmented nodular adrenocortical disease (PPNAD) and its non-pigmented variant, isolated micronodular adrenocortical disease. 'LDJQRVLV UHTXLUHV D QXPEHU RI VWHSV 7KH ¿UVW VWHS LV WR FKHFN WKH PHGLFDWLRQV D SHUVRQ WDNHV The second step is screening and confirmation of diagnosis: 24 h urine free cortisol (UFC), the 1 mg overnight (or two-day, 2 mg) dexamethasone suppression test, and late night salivary cortisol are recommended. To optimize sensitivity, guidelines recommend using the upper limit of the UHIHUHQFH UDQJH IRU 8)& DQG VDOLYDU\ FRUWLVRO DQG D FRUWLVRO FRQFHQWUDWLRQ OHVV WKDQ ā ȝJ G/ DIWHU dexamethasone as the cut-off for healthy responses. Patients with two abnormal screening test results can be diagnosed with Cushing’s syndrome. Once Cushing’s syndrome is diagnosed, the cause should EH LGHQWL¿HG WR GHWHUPLQH D VSHFL¿F WUHDWPHQW 7KH QH[W VWHS LQ WKH GLIIHUHQWLDO GLDJQRVLV RI &XVKLQJ¶V syndrome is measurement of plasma ACTH. A decreased plasma ACTH concentration in a patient usually suggests an adrenal cause and CT scan for adrenal gland is necessary. For ACTH-dependent Cushing’s syndrome, MRI of pituitary is the investigation of choice. If the differentiated diagnostic testing is ectopic ACTH syndrome, further image should include high-resolution CT scanning of the chest and abdomen.
58
