Nelson's Syndrome

What is Nelson's Syndrome?

Nelson's Syndrome is a rare condition that can develop after bilateral adrenalectomy, a surgery to remove both adrenal glands. This surgery is sometimes performed to treat severe Cushing's disease when other treatments have failed. After the adrenal glands are removed, the body can no longer produce cortisol on its own.

Without cortisol feedback to the brain, the pituitary gland may start to grow an aggressive tumor called a corticotroph adenoma. This tumor produces high levels of a hormone called ACTH, or adrenocorticotropic hormone. The high ACTH levels cause skin darkening and other symptoms. Nelson's Syndrome occurs in about 8 to 29 percent of people who have both adrenal glands removed for Cushing's disease.

The condition is named after Dr. Don Nelson, who first described it in 1958. Early detection through regular monitoring is important because the pituitary tumor can grow and press on nearby brain structures. With proper testing and treatment, most people with Nelson's Syndrome can manage the condition effectively.

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Symptoms

Skin darkening or hyperpigmentation, especially on the face, neck, and hands
Darkening of existing scars and skin folds
Headaches that may be severe or persistent
Vision problems including blurred vision or loss of peripheral vision
Fatigue and low energy levels
Loss of appetite
Nausea or vomiting
Changes in menstrual periods in women
Sexual dysfunction in men

Some people develop symptoms gradually over months or years. The skin darkening is often the first noticeable sign. Vision problems indicate that the tumor may be growing and pressing on the optic nerves.

Causes and risk factors

Nelson's Syndrome occurs when the pituitary gland loses the normal feedback signal from cortisol after both adrenal glands are removed. The pituitary gland normally releases ACTH to tell the adrenal glands to make cortisol. When cortisol levels are normal, the pituitary gland receives a signal to stop producing so much ACTH. After adrenalectomy, this feedback loop is broken because there are no adrenal glands to respond.

Without the cortisol feedback signal, pituitary cells that produce ACTH can grow unchecked and form a tumor. Risk factors for developing Nelson's Syndrome include younger age at the time of adrenalectomy, having a large pituitary tumor before surgery, and not receiving pituitary radiation therapy. Some studies suggest that up to 47 percent of people who do not receive preventive pituitary radiation may develop the condition. Genetic factors may also play a role in who develops this complication after surgery.

How it's diagnosed

Nelson's Syndrome is diagnosed through a combination of blood tests and imaging studies. Blood tests measure cortisol levels, which are expected to be low or undetectable after adrenalectomy. Your cortisol is monitored because you need to take replacement hormones for life. Rising ACTH levels over time can indicate that Nelson's Syndrome is developing. Regular monitoring of these hormone levels is essential for anyone who has had both adrenal glands removed.

MRI scans of the pituitary gland help detect tumor growth and monitor its size over time. Doctors typically recommend regular imaging every 6 to 12 months after adrenalectomy. Rite Aid offers cortisol testing through Quest Diagnostics at over 2,000 locations nationwide. Regular blood testing helps catch changes early so treatment can begin before the tumor causes serious complications.

Treatment options

Lifelong cortisol replacement therapy to replace what the adrenal glands would normally produce
Pituitary surgery to remove or reduce the tumor
Radiation therapy to shrink the tumor or prevent further growth
Medications like cabergoline or pasireotide to help control ACTH production
Regular monitoring with blood tests and MRI scans every 6 to 12 months
Vision testing to detect early changes from tumor pressure
Working with an endocrinologist who specializes in hormone disorders
Stress management, as physical stress requires adjusted cortisol doses
Medical alert identification showing that you need cortisol replacement

Frequently asked questions

Nelson's Syndrome develops after surgical removal of both adrenal glands for Cushing's disease. Without cortisol from the adrenal glands, the pituitary gland loses its normal feedback signal. This can cause pituitary cells to grow into an aggressive tumor that produces high levels of ACTH. The condition typically develops months to years after the surgery.

Nelson's Syndrome occurs in about 8 to 29 percent of people who have both adrenal glands removed for Cushing's disease. The risk varies based on several factors including age at surgery and whether preventive pituitary radiation is used. People who receive pituitary radiation have a lower risk. Regular monitoring helps detect the condition early when it does develop.

The earliest sign is often skin darkening or hyperpigmentation, especially on the face, neck, and hands. Existing scars may also darken noticeably. Rising ACTH levels on blood tests can detect the condition before symptoms appear. Headaches and vision changes are more serious signs that the tumor may be growing and require immediate medical attention.

Preventive pituitary radiation therapy after adrenalectomy can reduce the risk of developing Nelson's Syndrome. Some doctors recommend radiation for high-risk patients, while others prefer careful monitoring. The decision depends on individual risk factors and patient preferences. Regular blood testing and MRI scans help catch the condition early if it does develop.

Treatment usually involves surgery to remove the pituitary tumor, radiation therapy to shrink it, or both. Medications like cabergoline or pasireotide can help control ACTH production in some cases. Everyone with Nelson's Syndrome needs lifelong cortisol replacement therapy. Regular monitoring with blood tests and imaging is essential to track treatment response.

Cortisol testing monitors your replacement therapy to ensure you are getting the right dose. ACTH levels are measured regularly to detect rising hormone production from the pituitary tumor. Elevated ACTH with low cortisol after adrenalectomy strongly suggests Nelson's Syndrome. Testing every 3 to 6 months helps catch changes early.

High ACTH levels stimulate pigment cells in the skin called melanocytes. ACTH is chemically related to melanocyte-stimulating hormone, which controls skin pigmentation. The more ACTH in your blood, the darker your skin becomes. This darkening is most visible on sun-exposed areas, scars, and skin folds.

Yes, as the pituitary tumor grows, it can press on the optic nerves that control vision. This pressure can cause blurred vision, loss of peripheral vision, or double vision. Vision changes are a serious warning sign that needs immediate medical attention. Regular eye exams and MRI scans help detect tumor growth before vision is affected.

Yes, you need lifelong cortisol replacement therapy after both adrenal glands are removed. Your body cannot make cortisol on its own without adrenal glands. Missing doses can lead to a life-threatening adrenal crisis. You may need higher doses during illness, surgery, or physical stress.

After bilateral adrenalectomy, most doctors recommend blood testing every 3 to 6 months and MRI scans every 6 to 12 months. More frequent monitoring may be needed if your ACTH levels start to rise or symptoms develop. Regular testing allows early detection and treatment before the tumor causes serious complications. Your endocrinologist will create a monitoring schedule based on your individual risk factors.