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| Cushing's Syndrome |
Cushing's syndrome is a hormonal disorder caused by
prolonged exposure of the body's tissues to high levels of the
hormone cortisol. Sometimes called "hypercortisolism," it is
relatively rare and most commonly affects adults aged 20 to
50. An estimated 10 to 15 of every million people are affected
each year.
What are the symptoms?
Symptoms vary, but most people have upper body obesity,
rounded face, increased fat around the neck, and thinning
arms and legs. Children tend to be obese with slowed growth
rates.
Other symptoms appear in the skin, which becomes fragile and
thin. It bruises easily and heals poorly. Purplish pink stretch
marks may appear on the abdomen, thighs, buttocks, arms
and breasts. The bones are weakened, and routine activities
such as bending, lifting or rising from a chair may lead to
backaches, rib and spinal column fractures.
Most people have severe fatigue, weak muscles, high blood
pressure and high blood sugar. Irritability, anxiety and
depression are common.
Women usually have excess hair growth on their faces, necks,
chests, abdomens, and thighs. Their menstrual periods may
become irregular or stop. Men have decreased fertility with
diminished or absent desire for sex.
What causes Cushing's syndrome?
Cushing's syndrome occurs when the body's tissues are
exposed to excessive levels of cortisol for long periods of time.
Many people suffer the symptoms of Cushing's syndrome
because they take glucocorticoid hormones such as
prednisone for asthma, rheumatoid arthritis, lupus and other
inflammatory diseases, or for immunosuppression after
transplantation.
Others develop Cushing's syndrome because of
overproduction of cortisol by the body. Normally, the
production of cortisol follows a precise chain of events. First,
the hypothalamus, a part of the brain which is about the size
of a small sugar cube, sends corticotropin releasing hormone
(CRH) to the pituitary gland. CRH causes the pituitary to
secrete ACTH (adrenocorticotropin), a hormone that
stimulates the adrenal glands. When the adrenals, which are
located just above the kidneys, receive the ACTH, they
respond by releasing cortisol into the bloodstream.
Cortisol performs vital tasks in the body. It helps maintain
blood pressure and cardiovascular function, reduces the
immune system's inflammatory response, balances the effects
of insulin in breaking down sugar for energy, and regulates the
metabolism of proteins, carbohydrates, and fats. One of
cortisol's most important jobs is to help the body respond to
stress. For this reason, women in their last 3 months of
pregnancy and highly trained athletes normally have high levels
of the hormone. People suffering from depression, alcoholism,
malnutrition and panic disorders also have increased cortisol
levels.
When the amount of cortisol in the blood is adequate, the
hypothalamus and pituitary release less CRH and ACTH. This
ensures that the amount of cortisol released by the adrenal
glands is precisely balanced to meet the body's daily needs.
However, if something goes wrong with the adrenals or their
regulating switches in the pituitary gland or the hypothalamus,
cortisol production can go awry.
Pituitary Adenomas
Pituitary adenomas cause most cases of Cushing's syndrome.
They are benign, or non-cancerous, tumors of the pituitary
gland which secrete increased amounts of ACTH. Most patients
have a single adenoma. This form of the syndrome, known as
"Cushing's disease," affects women five times more frequently
than men.
Ectopic ACTH Syndrome
Some benign or malignant (cancerous) tumors that arise
outside the pituitary can produce ACTH. This condition is
known as ectopic ACTH syndrome. Lung tumors cause over 50
percent of these cases. Men are affected 3 times more
frequently than women. The most common forms of ACTH-
producing tumors are oat cell, or small cell lung cancer, which
accounts for about 25 percent of all lung cancer cases, and
carcinoid tumors. Other less common types of tumors that can
produce ACTH are thymomas, pancreatic islet cell tumors, and
medullary carcinomas of the thyroid.
Adrenal Tumors
Sometimes, an abnormality of the adrenal glands, most often
an adrenal tumor, causes Cushing's syndrome. The average
age of onset is about 40 years. Most of these cases involve
non-cancerous tumors of adrenal tissue, called adrenal
adenomas, which release excess cortisol into the blood.
Adrenocortical carcinomas, or adrenal cancers, are the least
common cause of Cushing's syndrome. Cancer cells secrete
excess levels of several adrenal cortical hormones, including
cortisol and adrenal androgens. Adrenocortical carcinomas
usually cause very high hormone levels and rapid development
of symptoms.
Familial Cushing's Syndrome
Most cases of Cushing's syndrome are not inherited. Rarely,
however, some individuals have special causes of Cushing's
syndrome due to an inherited tendency to develop tumors of
one or more endocrine glands. In Primary Pigmented
Micronodular Adrenal Disease, children or young adults develop
small cortisol-producing tumors of the adrenal glands. In
Multiple Endocrine Neoplasia Type I (MEN I), hormone secreting
tumors of the parathyroid glands, pancreas and pituitary
occur. Cushing's syndrome in MEN I may be due to pituitary,
ectopic or adrenal tumors.
How is Cushing's syndrome diagnosed?
Diagnosis is based on a review of the patient's medical history,
physical examination and laboratory tests. Often x-ray exams
of the adrenal or pituitary glands are useful for locating
tumors. These tests help to determine if excess levels of
cortisol are present and why.
24-Hour Urinary Free Cortisol Level
This is the most specific diagnostic test. The patient's urine is
collected over a 24-hour period and tested for the amount of
cortisol. Levels higher than 50–100 micrograms a day for an
adult suggest Cushing's syndrome. The normal upper limit
varies in different laboratories, depending on which
measurement technique is used.
Once Cushing's syndrome has been diagnosed, other tests are
used to find the exact location of the abnormality that leads to
excess cortisol production. The choice of test depends, in
part, on the preference of the endocrinologist or the center
where the test is performed.
Dexamethasone Suppression Test
This test helps to distinguish patients with excess production
of ACTH due to pituitary adenomas from those with ectopic
ACTH-producing tumors. Patients are given dexamethasone, a
synthetic glucocorticoid, by mouth every 6 hours for 4 days.
For the first 2 days, low doses of dexamethasone are given,
and for the last 2 days, higher doses are given. Twenty-four
hour urine collections are made before dexamethasone is
administered and on each day of the test. Since cortisol and
other glucocorticoids signal the pituitary to lower secretion of
ACTH, the normal response after taking dexamethasone is a
drop in blood and urine cortisol levels. Different responses of
cortisol to dexamethasone are obtained depending on whether
the cause of Cushing's syndrome is a pituitary adenoma or an
ectopic ACTH-producing tumor.
The dexamethasone suppression test can produce false-
positive results in patients with depression, alcohol abuse,
high estrogen levels, acute illness, and stress. Conversely,
drugs such as phenytoin and phenobarbital may cause false-
negative results in response to dexamethasone suppression.
For this reason, patients are usually advised by their
physicians to stop taking these drugs at least one week before
the test.
CRH Stimulation Test
This test helps to distinguish between patients with pituitary
adenomas and those with ectopic ACTH syndrome or cortisol-
secreting adrenal tumors. Patients are given an injection of
CRH, the corticotropin-releasing hormone which causes the
pituitary to secrete ACTH. Patients with pituitary adenomas
usually experience a rise in blood levels of ACTH and cortisol.
This response is rarely seen in patients with ectopic ACTH
syndrome and practically never in patients with cortisol-
secreting adrenal tumors.
Direct Visualization Endocrine Glands (Radiologic Imaging)
Imaging tests reveal the size and shape of the pituitary and
adrenal glands and help determine if a tumor is present. The
most common are the CT (computerized tomography) scan
and MRI (magnetic resonance imaging). A CT scan produces a
series of x-ray pictures giving a cross-sectional image of a
body part. MRI also produces images of the internal organs of
the body but without exposing the patient to ionizing radiation.
Imaging procedures are used to find a tumor after a diagnosis
has been established. Imaging is not used to make the
diagnosis of Cushing's syndrome because benign tumors,
sometimes called "incidentalomas," are commonly found in the
pituitary and adrenal glands. These tumors do not produce
hormones detrimental to health and are not removed unless
blood tests show they are a cause of symptoms or they are
unusually large. Conversely, pituitary tumors are not detected
by imaging in almost 50 percent of patients who ultimately
require pituitary surgery for Cushing's syndrome.
Petrosal Sinus Sampling
This test is not always required, but in many cases, it is the
best way to separate pituitary from ectopic causes of
Cushing's syndrome. Samples of blood are drawn from the
petrosal sinuses, veins which drain the pituitary, by
introducing catheters through a vein in the upper thigh/groin
region, with local anesthesia and mild sedation. X-rays are
used to confirm the correct position of the catheters. Often
CRH, the hormone which causes the pituitary to secrete ACTH,
is given during this test to improve diagnostic accuracy. Levels
of ACTH in the petrosal sinuses are measured and compared
with ACTH levels in a forearm vein. ACTH levels higher in the
petrosal sinuses than in the forearm vein indicate the presence
of a pituitary adenoma; similar levels suggest ectopic ACTH
syndrome.
The Dexamethasone-CRH Test
Some individuals have high cortisol levels, but do not develop
the progressive effects of Cushing's syndrome, such as
muscle weakness, fractures and thinning of the skin. These
individuals may have Pseudo Cushing's syndrome, which was
originally described in people who were depressed or drank
excess alcohol, but is now known to be more common. Pseudo
Cushing's does not have the same long-term effects on health
as Cushing's syndrome and does not require treatment
directed at the endocrine glands. Although observation over
months to years will distinguish Pseudo Cushing's from
Cushing's, the dexamethasone-CRH test was developed to
distinguish between the conditions rapidly, so that Cushing's
patients can receive prompt treatment. This test combines the
dexamethasone suppression and the CRH stimulation tests.
Elevations of cortisol during this test suggest Cushing's
syndrome.
Some patients may have sustained high cortisol levels without
the effects of Cushing's syndrome. These high cortisol levels
may be compensating for the body's resistance to cortisol's
effects. This rare syndrome of cortisol resistance is a genetic
condition that causes hypertension and chronic androgen
excess.
Sometimes other conditions may be associated with many of
the symptoms of Cushing's syndrome. These include
polycystic ovarian syndrome, which may cause menstrual
disturbances, weight gain from adolescence, excess hair
growth and sometimes impaired insulin action and diabetes.
Commonly, weight gain, high blood pressure and abnormal
levels of cholesterol and triglycerides in the blood are
associated with resistance to insulin action and diabetes; this
has been described as the "Metabolic Syndrome-X." Patients
with these disorders do not have abnormally elevated cortisol
levels.
How is Cushing's syndrome treated?
Treatment depends on the specific reason for cortisol excess
and may include surgery, radiation, chemotherapy or the use
of cortisol-inhibiting drugs. If the cause is long-term use of
glucocorticoid hormones to treat another disorder, the doctor
will gradually reduce the dosage to the lowest dose adequate
for control of that disorder. Once control is established, the
daily dose of glucocorticoid hormones may be doubled and
given on alternate days to lessen side effects.
Pituitary Adenomas
Several therapies are available to treat the ACTH-secreting
pituitary adenomas of Cushing's disease. The most widely
used treatment is surgical removal of the tumor, known as
transsphenoidal adenomectomy. Using a special microscope
and very fine instruments, the surgeon approaches the
pituitary gland through a nostril or an opening made below the
upper lip. Because this is an extremely delicate procedure,
patients are often referred to centers specializing in this type
of surgery. The success, or cure, rate of this procedure is over
80 percent when performed by a surgeon with extensive
experience. If surgery fails, or only produces a temporary cure,
surgery can be repeated, often with good results. After
curative pituitary surgery, the production of ACTH drops two
levels below normal. This is a natural, but temporary, drop in
ACTH production, and patients are given a synthetic form of
cortisol (such as hydrocortisone or prednisone). Most patients
can stop this replacement therapy in less than a year.
For patients in whom transsphenoidal surgery has failed or
who are not suitable candidates for surgery, radiotherapy is
another possible treatment. Radiation to the pituitary gland is
given over a 6-week period, with improvement occurring in 40
to 50 percent of adults and up to 80 percent of children. It
may take several months or years before patients feel better
from radiation treatment alone. However, the combination of
radiation and the drug mitotane (Lysodren®) can help speed
recovery. Mitotane suppresses cortisol production and lowers
plasma and urine hormone levels. Treatment with mitotane
alone can be successful in 30 to 40 percent of patients. Other
drugs used alone or in combination to control the production
of excess cortisol are aminoglutethimide, metyrapone,
trilostane and ketoconazole. Each has its own side effects that
doctors consider when prescribing therapy for individual
patients.
Ectopic ACTH Syndrome
To cure the overproduction of cortisol caused by ectopic ACTH
syndrome, it is necessary to eliminate all of the cancerous
tissue that is secreting ACTH. The choice of cancer treatment—
surgery, radiotherapy, chemotherapy, immunotherapy, or a
combination of these treatments—depends on the type of
cancer and how far it has spread. Since ACTH-secreting
tumors (for example, small cell lung cancer) may be very small
or widespread at the time of diagnosis, cortisol-inhibiting
drugs, like mitotane, are an important part of treatment. In
some cases, if pituitary surgery is not successful, surgical
removal of the adrenal glands (bilateral adrenalectomy) may
take the place of drug therapy.
Adrenal Tumors
Surgery is the mainstay of treatment for benign as well as
cancerous tumors of the adrenal glands. In Primary Pigmented
Micronodular Adrenal Disease and the familial Carney's
complex, surgical removal of the adrenal glands is required.
Content Source NIDDK.NIH
prolonged exposure of the body's tissues to high levels of the
hormone cortisol. Sometimes called "hypercortisolism," it is
relatively rare and most commonly affects adults aged 20 to
50. An estimated 10 to 15 of every million people are affected
each year.
What are the symptoms?
Symptoms vary, but most people have upper body obesity,
rounded face, increased fat around the neck, and thinning
arms and legs. Children tend to be obese with slowed growth
rates.
Other symptoms appear in the skin, which becomes fragile and
thin. It bruises easily and heals poorly. Purplish pink stretch
marks may appear on the abdomen, thighs, buttocks, arms
and breasts. The bones are weakened, and routine activities
such as bending, lifting or rising from a chair may lead to
backaches, rib and spinal column fractures.
Most people have severe fatigue, weak muscles, high blood
pressure and high blood sugar. Irritability, anxiety and
depression are common.
Women usually have excess hair growth on their faces, necks,
chests, abdomens, and thighs. Their menstrual periods may
become irregular or stop. Men have decreased fertility with
diminished or absent desire for sex.
What causes Cushing's syndrome?
Cushing's syndrome occurs when the body's tissues are
exposed to excessive levels of cortisol for long periods of time.
Many people suffer the symptoms of Cushing's syndrome
because they take glucocorticoid hormones such as
prednisone for asthma, rheumatoid arthritis, lupus and other
inflammatory diseases, or for immunosuppression after
transplantation.
Others develop Cushing's syndrome because of
overproduction of cortisol by the body. Normally, the
production of cortisol follows a precise chain of events. First,
the hypothalamus, a part of the brain which is about the size
of a small sugar cube, sends corticotropin releasing hormone
(CRH) to the pituitary gland. CRH causes the pituitary to
secrete ACTH (adrenocorticotropin), a hormone that
stimulates the adrenal glands. When the adrenals, which are
located just above the kidneys, receive the ACTH, they
respond by releasing cortisol into the bloodstream.
Cortisol performs vital tasks in the body. It helps maintain
blood pressure and cardiovascular function, reduces the
immune system's inflammatory response, balances the effects
of insulin in breaking down sugar for energy, and regulates the
metabolism of proteins, carbohydrates, and fats. One of
cortisol's most important jobs is to help the body respond to
stress. For this reason, women in their last 3 months of
pregnancy and highly trained athletes normally have high levels
of the hormone. People suffering from depression, alcoholism,
malnutrition and panic disorders also have increased cortisol
levels.
When the amount of cortisol in the blood is adequate, the
hypothalamus and pituitary release less CRH and ACTH. This
ensures that the amount of cortisol released by the adrenal
glands is precisely balanced to meet the body's daily needs.
However, if something goes wrong with the adrenals or their
regulating switches in the pituitary gland or the hypothalamus,
cortisol production can go awry.
Pituitary Adenomas
Pituitary adenomas cause most cases of Cushing's syndrome.
They are benign, or non-cancerous, tumors of the pituitary
gland which secrete increased amounts of ACTH. Most patients
have a single adenoma. This form of the syndrome, known as
"Cushing's disease," affects women five times more frequently
than men.
Ectopic ACTH Syndrome
Some benign or malignant (cancerous) tumors that arise
outside the pituitary can produce ACTH. This condition is
known as ectopic ACTH syndrome. Lung tumors cause over 50
percent of these cases. Men are affected 3 times more
frequently than women. The most common forms of ACTH-
producing tumors are oat cell, or small cell lung cancer, which
accounts for about 25 percent of all lung cancer cases, and
carcinoid tumors. Other less common types of tumors that can
produce ACTH are thymomas, pancreatic islet cell tumors, and
medullary carcinomas of the thyroid.
Adrenal Tumors
Sometimes, an abnormality of the adrenal glands, most often
an adrenal tumor, causes Cushing's syndrome. The average
age of onset is about 40 years. Most of these cases involve
non-cancerous tumors of adrenal tissue, called adrenal
adenomas, which release excess cortisol into the blood.
Adrenocortical carcinomas, or adrenal cancers, are the least
common cause of Cushing's syndrome. Cancer cells secrete
excess levels of several adrenal cortical hormones, including
cortisol and adrenal androgens. Adrenocortical carcinomas
usually cause very high hormone levels and rapid development
of symptoms.
Familial Cushing's Syndrome
Most cases of Cushing's syndrome are not inherited. Rarely,
however, some individuals have special causes of Cushing's
syndrome due to an inherited tendency to develop tumors of
one or more endocrine glands. In Primary Pigmented
Micronodular Adrenal Disease, children or young adults develop
small cortisol-producing tumors of the adrenal glands. In
Multiple Endocrine Neoplasia Type I (MEN I), hormone secreting
tumors of the parathyroid glands, pancreas and pituitary
occur. Cushing's syndrome in MEN I may be due to pituitary,
ectopic or adrenal tumors.
How is Cushing's syndrome diagnosed?
Diagnosis is based on a review of the patient's medical history,
physical examination and laboratory tests. Often x-ray exams
of the adrenal or pituitary glands are useful for locating
tumors. These tests help to determine if excess levels of
cortisol are present and why.
24-Hour Urinary Free Cortisol Level
This is the most specific diagnostic test. The patient's urine is
collected over a 24-hour period and tested for the amount of
cortisol. Levels higher than 50–100 micrograms a day for an
adult suggest Cushing's syndrome. The normal upper limit
varies in different laboratories, depending on which
measurement technique is used.
Once Cushing's syndrome has been diagnosed, other tests are
used to find the exact location of the abnormality that leads to
excess cortisol production. The choice of test depends, in
part, on the preference of the endocrinologist or the center
where the test is performed.
Dexamethasone Suppression Test
This test helps to distinguish patients with excess production
of ACTH due to pituitary adenomas from those with ectopic
ACTH-producing tumors. Patients are given dexamethasone, a
synthetic glucocorticoid, by mouth every 6 hours for 4 days.
For the first 2 days, low doses of dexamethasone are given,
and for the last 2 days, higher doses are given. Twenty-four
hour urine collections are made before dexamethasone is
administered and on each day of the test. Since cortisol and
other glucocorticoids signal the pituitary to lower secretion of
ACTH, the normal response after taking dexamethasone is a
drop in blood and urine cortisol levels. Different responses of
cortisol to dexamethasone are obtained depending on whether
the cause of Cushing's syndrome is a pituitary adenoma or an
ectopic ACTH-producing tumor.
The dexamethasone suppression test can produce false-
positive results in patients with depression, alcohol abuse,
high estrogen levels, acute illness, and stress. Conversely,
drugs such as phenytoin and phenobarbital may cause false-
negative results in response to dexamethasone suppression.
For this reason, patients are usually advised by their
physicians to stop taking these drugs at least one week before
the test.
CRH Stimulation Test
This test helps to distinguish between patients with pituitary
adenomas and those with ectopic ACTH syndrome or cortisol-
secreting adrenal tumors. Patients are given an injection of
CRH, the corticotropin-releasing hormone which causes the
pituitary to secrete ACTH. Patients with pituitary adenomas
usually experience a rise in blood levels of ACTH and cortisol.
This response is rarely seen in patients with ectopic ACTH
syndrome and practically never in patients with cortisol-
secreting adrenal tumors.
Direct Visualization Endocrine Glands (Radiologic Imaging)
Imaging tests reveal the size and shape of the pituitary and
adrenal glands and help determine if a tumor is present. The
most common are the CT (computerized tomography) scan
and MRI (magnetic resonance imaging). A CT scan produces a
series of x-ray pictures giving a cross-sectional image of a
body part. MRI also produces images of the internal organs of
the body but without exposing the patient to ionizing radiation.
Imaging procedures are used to find a tumor after a diagnosis
has been established. Imaging is not used to make the
diagnosis of Cushing's syndrome because benign tumors,
sometimes called "incidentalomas," are commonly found in the
pituitary and adrenal glands. These tumors do not produce
hormones detrimental to health and are not removed unless
blood tests show they are a cause of symptoms or they are
unusually large. Conversely, pituitary tumors are not detected
by imaging in almost 50 percent of patients who ultimately
require pituitary surgery for Cushing's syndrome.
Petrosal Sinus Sampling
This test is not always required, but in many cases, it is the
best way to separate pituitary from ectopic causes of
Cushing's syndrome. Samples of blood are drawn from the
petrosal sinuses, veins which drain the pituitary, by
introducing catheters through a vein in the upper thigh/groin
region, with local anesthesia and mild sedation. X-rays are
used to confirm the correct position of the catheters. Often
CRH, the hormone which causes the pituitary to secrete ACTH,
is given during this test to improve diagnostic accuracy. Levels
of ACTH in the petrosal sinuses are measured and compared
with ACTH levels in a forearm vein. ACTH levels higher in the
petrosal sinuses than in the forearm vein indicate the presence
of a pituitary adenoma; similar levels suggest ectopic ACTH
syndrome.
The Dexamethasone-CRH Test
Some individuals have high cortisol levels, but do not develop
the progressive effects of Cushing's syndrome, such as
muscle weakness, fractures and thinning of the skin. These
individuals may have Pseudo Cushing's syndrome, which was
originally described in people who were depressed or drank
excess alcohol, but is now known to be more common. Pseudo
Cushing's does not have the same long-term effects on health
as Cushing's syndrome and does not require treatment
directed at the endocrine glands. Although observation over
months to years will distinguish Pseudo Cushing's from
Cushing's, the dexamethasone-CRH test was developed to
distinguish between the conditions rapidly, so that Cushing's
patients can receive prompt treatment. This test combines the
dexamethasone suppression and the CRH stimulation tests.
Elevations of cortisol during this test suggest Cushing's
syndrome.
Some patients may have sustained high cortisol levels without
the effects of Cushing's syndrome. These high cortisol levels
may be compensating for the body's resistance to cortisol's
effects. This rare syndrome of cortisol resistance is a genetic
condition that causes hypertension and chronic androgen
excess.
Sometimes other conditions may be associated with many of
the symptoms of Cushing's syndrome. These include
polycystic ovarian syndrome, which may cause menstrual
disturbances, weight gain from adolescence, excess hair
growth and sometimes impaired insulin action and diabetes.
Commonly, weight gain, high blood pressure and abnormal
levels of cholesterol and triglycerides in the blood are
associated with resistance to insulin action and diabetes; this
has been described as the "Metabolic Syndrome-X." Patients
with these disorders do not have abnormally elevated cortisol
levels.
How is Cushing's syndrome treated?
Treatment depends on the specific reason for cortisol excess
and may include surgery, radiation, chemotherapy or the use
of cortisol-inhibiting drugs. If the cause is long-term use of
glucocorticoid hormones to treat another disorder, the doctor
will gradually reduce the dosage to the lowest dose adequate
for control of that disorder. Once control is established, the
daily dose of glucocorticoid hormones may be doubled and
given on alternate days to lessen side effects.
Pituitary Adenomas
Several therapies are available to treat the ACTH-secreting
pituitary adenomas of Cushing's disease. The most widely
used treatment is surgical removal of the tumor, known as
transsphenoidal adenomectomy. Using a special microscope
and very fine instruments, the surgeon approaches the
pituitary gland through a nostril or an opening made below the
upper lip. Because this is an extremely delicate procedure,
patients are often referred to centers specializing in this type
of surgery. The success, or cure, rate of this procedure is over
80 percent when performed by a surgeon with extensive
experience. If surgery fails, or only produces a temporary cure,
surgery can be repeated, often with good results. After
curative pituitary surgery, the production of ACTH drops two
levels below normal. This is a natural, but temporary, drop in
ACTH production, and patients are given a synthetic form of
cortisol (such as hydrocortisone or prednisone). Most patients
can stop this replacement therapy in less than a year.
For patients in whom transsphenoidal surgery has failed or
who are not suitable candidates for surgery, radiotherapy is
another possible treatment. Radiation to the pituitary gland is
given over a 6-week period, with improvement occurring in 40
to 50 percent of adults and up to 80 percent of children. It
may take several months or years before patients feel better
from radiation treatment alone. However, the combination of
radiation and the drug mitotane (Lysodren®) can help speed
recovery. Mitotane suppresses cortisol production and lowers
plasma and urine hormone levels. Treatment with mitotane
alone can be successful in 30 to 40 percent of patients. Other
drugs used alone or in combination to control the production
of excess cortisol are aminoglutethimide, metyrapone,
trilostane and ketoconazole. Each has its own side effects that
doctors consider when prescribing therapy for individual
patients.
Ectopic ACTH Syndrome
To cure the overproduction of cortisol caused by ectopic ACTH
syndrome, it is necessary to eliminate all of the cancerous
tissue that is secreting ACTH. The choice of cancer treatment—
surgery, radiotherapy, chemotherapy, immunotherapy, or a
combination of these treatments—depends on the type of
cancer and how far it has spread. Since ACTH-secreting
tumors (for example, small cell lung cancer) may be very small
or widespread at the time of diagnosis, cortisol-inhibiting
drugs, like mitotane, are an important part of treatment. In
some cases, if pituitary surgery is not successful, surgical
removal of the adrenal glands (bilateral adrenalectomy) may
take the place of drug therapy.
Adrenal Tumors
Surgery is the mainstay of treatment for benign as well as
cancerous tumors of the adrenal glands. In Primary Pigmented
Micronodular Adrenal Disease and the familial Carney's
complex, surgical removal of the adrenal glands is required.
Content Source NIDDK.NIH
| MEDICAL NOTES |