Cushing's syndrome: Diagnosis & Treatments
Diagnosis
The diagnosis of Cushing's syndrome begins with identifying and abolishing the history of the disease, such as when taking herbal medicines, taking steroids, or injecting intra-articular steroids.
There were three screening tests: the first one was overnight 1 mg dexamethasone suppression test, and the first one was dexamethasone 1 mg at 11 o'clock the night before, and the next day at 8 o'clock, plasma cortisol was measured at 1.8 ug / dL Or more. This test is called pseudo-cushing's syndrome, which is very likely to be false, because it is very diverse, including obesity, depression, alcoholism, acute infection / trauma, and pregnancy. Re-measurement after removal and supplementation to other tests are necessary. The second is a 24hr urinary for cortisol excretion test, which is positive if the urine collected from the urine collected for 24 hours is higher than normal or the concentration is increased more than 3 times. The third screening test is positive if the circadian rhythm of plasma cortisol / midnight cortisol exceeds 5 ug / dL. The reason for such a test is based on the disappearance of the circadian rhythm of cortisol at high doses of cortisol secreted at night, the physiologically lowest cortisol release. If a positive result is found on screening, a diagnosis of cushing's syndrome is confirmed through a confirmatory test. Confirmatory tests were performed with a low dose dexamethasone suppression test at 0.5 mg dexamethasone every 6 hours for 2 days and confirmed at plasma cortisol> 1.8 ug / dl.
When Cushing's syndrome is confirmed, differential diagnosis should be performed to find the cause of increased cortisol. As discussed earlier, ACTH is measured because ACTH is dependent / independent. In the case of ACTH higher than 5 pmol / L, the cortisol concentration is elevated because of increased ACTH concentration, and it includes pituitary microadenoma, pituitary microadenoma, and ectopic ACTH (or CRH) -producing tumor. When ACTH is suppressed at low concentration, there is adrenal neoplasm in which cortisol is increased regardless of ACTH concentration.
Additional tests are needed to distinguish between ACTH-dependent and pituitary problems. Sella MRI is used to identify pituitary lesions, and high-dose dexamethasone suppression tests and CRH infusion tests. Both tests indicate a pituitary microadenoma when benign findings appear. If both are negative, ectopic ACTH can be confirmed, and if equivocal, IPSS will be performed. IPSS is used in clinical, imaging, cushing's dz. It is a test to be performed when it is difficult to differentiate from ectopic ACTH. It proceeds by measuring the ACTH concentration at 2, 5 and 10 min after drug administration and 1 ug / kg of CRH.
Any cushing's syndrome should be localized by imaging. Cushing's disease (pituitary ACTH-producing adenoma) can be detected by MRI as previously described, and SCLC and bronchial carcinoid (chest) in ectopic ACTH production. Adrenal neoplasm is possible with abdominal CT and adrenal scan: 19- [131I] iodo-cholesterol scanning.
Treatments
In the case of Cushing's syndrome, trans-sphenoidal resection is TOC. When surgery is not possible, drugs such as mitotane, metyrapone, and ketoconazole, which target the adrenal cortex to block the function or block the enzyme that makes cortisol, need to be supplemented after steroids. Ectopic ACTH treats the underlying tumors and treats both corticosteroids with both adrenalectomy or medical treatment. In the case of adrenal neoplasm, adenoma performs surgery and carcinoma treats surgery and mitotane.
The diagnosis of Cushing's syndrome begins with identifying and abolishing the history of the disease, such as when taking herbal medicines, taking steroids, or injecting intra-articular steroids.
There were three screening tests: the first one was overnight 1 mg dexamethasone suppression test, and the first one was dexamethasone 1 mg at 11 o'clock the night before, and the next day at 8 o'clock, plasma cortisol was measured at 1.8 ug / dL Or more. This test is called pseudo-cushing's syndrome, which is very likely to be false, because it is very diverse, including obesity, depression, alcoholism, acute infection / trauma, and pregnancy. Re-measurement after removal and supplementation to other tests are necessary. The second is a 24hr urinary for cortisol excretion test, which is positive if the urine collected from the urine collected for 24 hours is higher than normal or the concentration is increased more than 3 times. The third screening test is positive if the circadian rhythm of plasma cortisol / midnight cortisol exceeds 5 ug / dL. The reason for such a test is based on the disappearance of the circadian rhythm of cortisol at high doses of cortisol secreted at night, the physiologically lowest cortisol release. If a positive result is found on screening, a diagnosis of cushing's syndrome is confirmed through a confirmatory test. Confirmatory tests were performed with a low dose dexamethasone suppression test at 0.5 mg dexamethasone every 6 hours for 2 days and confirmed at plasma cortisol> 1.8 ug / dl.
When Cushing's syndrome is confirmed, differential diagnosis should be performed to find the cause of increased cortisol. As discussed earlier, ACTH is measured because ACTH is dependent / independent. In the case of ACTH higher than 5 pmol / L, the cortisol concentration is elevated because of increased ACTH concentration, and it includes pituitary microadenoma, pituitary microadenoma, and ectopic ACTH (or CRH) -producing tumor. When ACTH is suppressed at low concentration, there is adrenal neoplasm in which cortisol is increased regardless of ACTH concentration.
Additional tests are needed to distinguish between ACTH-dependent and pituitary problems. Sella MRI is used to identify pituitary lesions, and high-dose dexamethasone suppression tests and CRH infusion tests. Both tests indicate a pituitary microadenoma when benign findings appear. If both are negative, ectopic ACTH can be confirmed, and if equivocal, IPSS will be performed. IPSS is used in clinical, imaging, cushing's dz. It is a test to be performed when it is difficult to differentiate from ectopic ACTH. It proceeds by measuring the ACTH concentration at 2, 5 and 10 min after drug administration and 1 ug / kg of CRH.
Any cushing's syndrome should be localized by imaging. Cushing's disease (pituitary ACTH-producing adenoma) can be detected by MRI as previously described, and SCLC and bronchial carcinoid (chest) in ectopic ACTH production. Adrenal neoplasm is possible with abdominal CT and adrenal scan: 19- [131I] iodo-cholesterol scanning.
Treatments
In the case of Cushing's syndrome, trans-sphenoidal resection is TOC. When surgery is not possible, drugs such as mitotane, metyrapone, and ketoconazole, which target the adrenal cortex to block the function or block the enzyme that makes cortisol, need to be supplemented after steroids. Ectopic ACTH treats the underlying tumors and treats both corticosteroids with both adrenalectomy or medical treatment. In the case of adrenal neoplasm, adenoma performs surgery and carcinoma treats surgery and mitotane.
