Nelson syndrome is a rare disorder which occurs in some of the patients of Cushing disease after the removal of adrenal glands. It is characterized by the signs and symptoms due to enlargement of ACTH secreting tumor in the pituitary gland and the abnormal hormone concentration produced by it. The patient complaints of intense skin discoloration, headaches or vision impairment.
Not all patient of nelson syndrome who undergoes removal of their adrenal glands suffer from nelson syndrome, studies shows that about 15-25 percent of these people suffer from this.
The signs and symptoms arise due to hormonal imbalance and mass effect of pituitary tumor
Due to hormonal imbalance: The increased concentration of ACTH and beta-MSH hormone causes
Due to size effect of pituitary tumor: The enlarging pituitary tumor compresses the normal pituitary itself as well as the surrounding structures causing
It exclusively occurs in the people who had Cushing diseases in the past and they had removed both of their adrenal glands. Normally, hypothalamus which a small gland of the brain instructs pituitary to release ACTH hormone that causes adrenal glands to produce Cortisol and other hormones. In Cushing disease, pituitary tumor causes increased production of adrenal glands hormone due to increased levels of ACTH. Increased levels of adrenal glands hormone cause a feedback inhibition on pituitary gland as well as hypothalamus but after the removal of adrenal glands there is no feedback inhibition and the size of that pituitary tumors goes on increasing, producing the mass effects.
The diagnosis is easy and your doctor uses your medical history, physical examination and order some test to establish a diagnosis
Medical history: Your doctor will ask you some questions about your symptoms, past illness and treatment history. The doctor will suspect the nelson syndrome if there is past history of Cushing syndrome with removal of adrenal glands and symptoms suggestive of pituitary enlargement.
Physical examination: The doctor will examine your body from head to the toe, looking for the signs and symptoms of various hormone deficiency. A visual field test can be used to check for any defects in the vision.
Blood hormone level: your blood sample is taken and level of ACTH hormone is measured. On the basis of the medical history, the levels of other hormones can be checked of your doctor suspects the deficiency of pituitary hormones
Imaging tests: MRI scan can be used to assess the growth of the pituitary tumor and to look for the effects on the areas in the brain around the pituitary gland.
The main goal of the treatment is to remove the cause of the nelson syndrome. The surgical excision is the ideal treatment but not possible always.
Radiation: The radiation therapy can be used to limit the abnormal growth of the pituitary gland if the size is not large enough, today stereotactic radiosurgery is available nowadays that can deliver highly focused dose of radiation which doesn’t harm the surrounding structures.
Surgical excision: The best way to approach is through nose but large tumors are approached through skull.
Pharmacological treatment: These are not effective as much but some medicines can be used to shrink the tumor size and to control the symptoms.