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Adrenal Cancer
Overview
Adrenal cancer is a rare disease that originates in the adrenal glands. The
adrenal glands are located on top of the kidneys and consist of two parts that
function separately: the cortex (outer layer) and the medulla (inner area).
The cortex produces three major hormones: cortisol (a glucocorticoid),
aldosterone (a mineralocorticoid), and dehydroepiandrosterone (DHEA; an
androgen). The medulla produces epinephrine (adrenaline), norepinephrine, and
dopamine.
Adrenal tumors can be functioning (i.e., increase hormone production) or
nonfunctioning (i.e., do not produce hormones). Symptoms of adrenal cancer and
treatment for the condition depend on whether the tumor is functioning or
nonfunctioning, and on which hormone is being overproduced.
Types
Most (99%) adrenal tumors are benign (i.e., noncancerous) adrenal cortical
adenomas and do not require treatment. These tumors usually do not cause
symptoms, are small, and are found incidentally during diagnostic imaging.
The most common type of adrenal cancer develops in the adrenal cortex and is
called adrenocortical carcinoma. Functioning adrenocortical carcinomas
may produce symptoms related to increased hormone production.
Nonfunctioning tumors may cause pain from pressure on abdominal organs and a
palpable (able to be felt with the fingers) mass in the abdomen.
Cancers that develop in the adrenal medulla include neuroblastoma
(originates in undeveloped nerve cells) and pheochromocytoma (originates
in cells that produce epinephrine and norephinephrine). Neuroblastoma usually
occurs in infants and children and pheochromocytoma more commonly occurs in
people who are in their 30s and 40s.
Other types of cancer (e.g., breast, lung) may spread (metastasize) to the
adrenal glands.
Incidence and Prevalence
Worldwide, about 1 out of 1 million people develop adrenal cancer each year.
Prevalence of the condition is slightly higher in men in their 40s and 50s and
in children younger than 5 years old.
Causes and Risk Factors
The cause of adrenal cancer is unknown and most cases do not have
identifiable risk factors. In some cases, heredity plays a role in the
development of the disease. Li-Fraumeni syndrome and type 1 multiple endocrine
neoplasia (MEN1) are genetic mutations in tumor suppressor genes that increase
the risk for several types of cancer, including adrenal cancer. Genetic testing
may be recommended in families with a high incidence of suspected tumor
suppressor gene mutation.
Other familial syndromes associated with adrenal cancer include:
- Gardner syndrome
- Carney triad
- Cowden syndrome
- Familial polyposis
- Turcot syndrome
Signs and
Symptoms
Adrenal cancer does not always produce symptoms. Both nonfunctioning
adrenocortical carcinomas and large functioning tumors may cause the following:
- Fever
- Palpable (able to be felt with the fingers) abdominal mass
- Persistent abdominal pain
- Sensation of abdominal "fullness"
- Weight loss
Additional symptoms of functioning adrenocortical carcinoma depend on
which hormones are overproduced. Overproduction of androgens (e.g.,
dehydroepiandrosterone, estrogen) usually does not produce symptoms in men
because the testicles produce testosterone, which is a more potent androgen.
Rarely, abnormal breast enlargement (gynecomastia) occurs in men. Excess
androgens may cause early puberty in children and masculination (i.e., abnormal
facial and body hair, deepening voice) in women and children.
Complications
A functioning adrenocortical tumor that produces excess cortisol may result
in Cushing’s syndrome. Approximately 30–40% of patients with Cushing
syndrome and an adrenal mass are diagnosed with adrenal cancer. Symptoms of
Cushing syndrome include the following:
- Abdominal striae (stretch marks)
- Absence of menstruation (amenorrhea)
- Bruising easily
- Excessive growth of facial and body hair in women (hirsutism)
- Flushing (reddish complexion)
- High blood pressure (hypertension)
- Hyperglycemia (increased blood sugar, diabetes)
- Increased body fat (adiposity) in the face, neck, and abdomen
- Severe acne
- Slowed growth rate (in children)
- Osteoporosis (loss of bone mass, may cause spinal curvature)
- Weakness and muscle wasting
Conn’s syndrome is caused by increased aldosterone production and may
result from a functioning tumor in the adrenal cortex. Symptoms of Conn syndrome
include the following:
- Chronic excessive thirst (polydipsia)
- Excessive urination (polyuria)
- High blood pressure (hypertension)
- Low level of potassium in the blood (hypokalemia)
The hallmark of pheochromocytoma is sudden or sustained high blood
pressure (hypertension) that is often resistant to treatment. Other symptoms
include severe headaches, sweating, heart palpitations (rapid pulse), and
nausea.
Symptoms of neuroblastoma include abdominal pain and bone pain
resulting from metastatic disease.
Diagnosis
Diagnosis of adrenal cancer involves taking a medical history and performing
a physical examination, blood and urine tests, imaging tests, and a biopsy.
Medical history includes family history of adrenal cancer, menstrual (in women)
and sexual history, and the patient’s history of symptoms. Physical examination
includes palpating (feeling with the fingers) the abdomen for evidence of an
adrenal mass.
Blood and Urine Tests
Blood and urine tests are used to detect elevated levels of hormones (e.g.,
cortisol, aldosterone) and other substances (e.g., potassium). The patient’s
symptoms determine which tests are performed.
Imaging Tests
Computed tomography (CT scan) and magnetic resonance imaging (MRI) are the
imaging studies of choice used to produce images of the adrenal gland and
identify abnormal enlargement or tumors.
CT scan uses x-rays to produce detailed images of the adrenal glands,
other abdominal organs, and lymph nodes. In some cases, a contrast agent (dye)
is used to detect metastasis.
MRI uses magnetic fields to produce a cross-sectional image that
detects abnormal enlargement of the adrenal gland. This test may be used to help
determine if adrenal tumors are benign or malignant (cancerous).
Biopsy
Biopsy is the surgical removal of cells or tissue for microscopic evaluation.
This procedure may be used to evaluate an adrenal mass for cancer cells. During
biopsy, ultrasound or CT scan is used to guide a needle into the tumor to remove
cells (called a fine needle aspirate) or a larger amount of tissue (called core
tissue biopsy). The cells are then examined under a microscope and if malignant
(cancerous) cells are found, the cancer is staged.
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