Cushing’s Syndrome

The condition of cortisol excess is called Cushing’s syndrome. It can be due to excess secretion of cortisol either due to a problem in adrenal gland it self or due to excess secretion of ACTH, the Pituitary hormone that controls cortisol secretion. The latter situation can be either due to ACTH coming from pituitary or coming from some cancerous lesions, when it is called ectopic secretion of ACTH. The reason for the adrenal gland to produce excess of cortisol could be a tumor which is either benign or cancerous. However the most common reason being the condition called iatrogenic Cushing’s which is caused due excess intake of steroid drugs for some reason or other.

The patients suffering from this disorder may have following picture. They can have a round face, a buffalo hump (collection of fat in the back just below the neck), weakness of muscles resulting in difficulty in getting up from the sitting position, weakness of bone (osteoporosis) resulting in easy fractures, menstrual disturbances, thinning of the skin, raised blood pressure and high blood sugar. Many experience mood disturbances like depression. Loss of sexual drive can be another problem. Many become susceptible to infections.

adrenal_4

When a person has clinical features suggestive of Cushing’s syndrome the clinician looks for evidence of increased cortisol production. He would order for measurement of blood cortisol at 8 am and midnight. If they are high then a tablet called dexamethasone will be given at 11pm and your blood will be tested next morning at 8 am for cortisol level. In normal persons there will be low level of cortisol in the next morning but if it is high then the suspicion of Cushing’s syndrome is strong. From here he proceeds to find out if this excess is coming from adrenals or from ACTH excess. Estimation of ACTH value, which is done only at a few centers in India, helps solve this problem. While in the former ACTH is undetectable in the latter it is high. If ACTH is found to be high then it could be of either pituitary source or of an ectopic source. A MRI scan of the pituitary or CT scan of abdomen or chest can reveal the culprit.

If the cause is in the pituitary then a surgery called Trans sphenoidal surgery is done to remove the tumor from the pituitary. It may be followed by radiotherapy in case of failure of surgery. If it is located in the adrenal then either one or both glands are removed. We have two options here. One is an open surgery second one is laparoscopic surgery. In the latter the advantage is that a small cut is needed and recovery is faster. However it is useful only if size is less than six cms. If it is more than six cms then probability that it could be cancerous lesion are high, whence open surgery is preferable. In either case one has to be on replacement of the hormones in appropriate dose later. If it is an ectopic source then an attempt is made to remove the source. But in case it is not possible then certain drugs like ketoconazole or metyrapone are given to suppress the cortisol production.