|See how our team connects in diagnosing and treating endocrine diseases.|
|Parathyroid Disease||Adrenal Tumors|
|Thyroid Disease||Pancreatic Endocrine Disease|
We all normally have four parathyroid glands located in our necks, which produce Parathyroid Hormone (PTH) to control the amount of calcium in our blood, nervous system and bones. If a tumor develops on these glands, it is called parathyroid disease, or hyperparathyroidism. These tumors can cause the glands to produce more hormone than needed (hyper means excessive), resulting in unhealthy, elevated levels of blood calcium, as well as a loss of needed calcium in the bones (osteoporosis) and the potential formation of kidney stones.
In most patients – approximately 80 percent – a tumor forms in the gland. This tumor is called a parathyroid adenoma and causes over-production of hormone. The remaining 20 percent may be caused by external factors, such as renal failure or other conditions. Parathyroid disease may rarely be caused by genetic mutations shared within families.
Parathyroid cancer is extremely rare – about 1 in 2 million. Most parathyroid tumors are benign, or non-cancerous. However, some patients have developed other cancers after having been diagnosed with hyperparathyroidism leading some to speculate on whether or not tumors of the parathyroid can lead to other cancers. At this time, however, there is no evidence to link hyperparathyroidism with development of other cancers. More research has to be done in this area.
Calcium is essential in maintaining many important body functions. We all know that calcium is important in maintaining strong, health bones and teeth. But it’s also vital to our heart, nervous system and kidneys. When working properly, our parathyroid glands produce just the right amount of PTH to keep the perfect balance of calcium in our bones, blood and nervous system. If too much is produced, due to a tumor in the parathyroid gland, we call this hyperparathyroidism, or parathyroid disease.
Unfortunately, the symptoms of parathyroid disease can be somewhat vague or even general. Some patients complain of fatigue, memory loss, irritability, leg or bone pain, headaches, constipation, kidney stones and higher blood pressure.
Generally, women over the age of 45 are more likely to develop an overactive parathyroid, but it occurs in both men and women of all ages.
The diagnosis is made by measuring blood calcium, blood parathyroid hormone and, sometimes, urine calcium levels. The diagnosis cannot be made by radiologic studies. Many times, the location of the parathyroid tumor can be identified by using an ultrasound, a nuclear medicine scan “parathyroid” scan, or a CT scan. Not finding a parathyroid tumor on scans/ultrasound does not mean a person does not have hyperparathyroidism.
The only treatment for an overactive parathyroid gland is surgical removal. Most of our patients at Vanderbilt go home just hours after a minimally invasive parathyroid procedure. The procedure requires only a small incision over the base of the neck.
THYROID DISEASE back to top
First let’s understand what the thyroid gland does. When working properly, the thyroid is a vital component of our endocrine system. The thyroid produces thyroid hormone which is released into the bloodstream to regulate our body’s metabolism. The pituitary gland in the brain actually controls the amount of thyroid hormone released by producing Thyroid Stimulating Hormone, or TSH. An overactive or underactive thyroid can cause diseases of the thyroid, as can nodules in the thyroid. Many patients are found to have thyroid nodules, yet their thyroid continues to work normally.
Not all thyroid disease is cancerous. Most thyroid nodules and goiters are benign (~80%), as are both hypo- and hyperthyroidism.
If nodules are cancerous, and this is rare, the treatment varies by type. The most common types of thyroid cancer are called well-differentiated (papillary and follicular) and are generally treated with thyroid removal. Less common cancers of the thyroid are called medullary and anaplastic thyroid cancer, which may require more aggressive treatment.
Hypothyroid disease can cause fatigue, weight gain, constipation, water retention, thinning hair, dry skin and difficulty concentrating.
Hyperthyroidism may be associated with anxiety, insomnia, tremors, weight loss, muscle weakness, excessive sweating and menstrual changes.
There is significant overlap in symptoms of thyroid hormone changes and it varies between patients.
Nodules, sometimes called goiter, may cause trouble swallowing, feeling of choking or pressure in the neck, or no symptoms at all.
Both hypothyroidism and hyperthyroidism are more common in women.
Hypothyroidism is often seen in patients who have a personal history of autoimmune diseases, have had radioactive iodine treatment, have low iodine in their diets, or are taking certain medications such as lithium or amiodarone.
Hyperthyroidism is most common in patients with Graves’ disease, an autoimmune system problem that overstimulates the thyroid. One or more growths in the thyroid can also cause overproduction of thyroid hormone. These growths are called toxic multinodular goiter and toxic adenoma, but are far less common a cause than Graves’ disease.
Thyroid cancer, which is rare, can occur in men and women, depending on cancer type.
We can test thyroid function by assessing levels of thyroid stimulating hormone (TSH) in the blood, specifically TSH not associated with proteins, but free-standing hormones. These tests are more accurate than measuring total hormone levels present in the blood. We can also test for the presence of antithyroid antibodies, as well as calcitonin.
Nodules can be diagnosed by ultrasound or fine needle aspiration biopsy, in which a sample of cells in the thyroid are removed and examined under a microscope.
Hypothyroidism can be treated with a pill form of thyroid hormone.
Hyperthyroidism is usually treated first with Beta blockers to control the symptoms, followed by antithyroid medications to block excess thyroid hormone production. In many patients, it is necessary to provide other definitive treatments such as thyroidectomy. Removing the entire thyroid and starting thyroid replacement therapy offers the strongest results with only a <1% recurrence rate. Another treatment plan is called Radioiodine ablation (RAI). Patients are given a pill of radioactive iodine to destroy the thyroid cells and avoid surgery. However, RAI ablation may worsen hyperthyroid eye disease, if present. It does not remove large thyroid tumors and may require treatment.
Cancerous nodules may be treated by surgery, TSH suppression and potentially radioiodine treatment. “Traditional” types of chemotherapy and radiation therapy are rarely ever indicated in thyroid cancer.
ADRENAL TUMORS back to top
We normally have two small adrenal glands that sit atop our kidneys. The center of these glands, known as the medulla, produces hormones that prompt a “fight or flight response” to help our bodies prepare for potentially stressful or dangerous situations. They increase our heart rate, blood pressure and the amount of oxygen we breathe in, as well as temporarily improve eyesight and cause the liver to release extra glucose, or sugar, for immediate energy. It’s what we call an adrenaline rush.
The outer layer of the glands, known as the cortex, produces hormones that control functions of the heart, kidneys, gastrointestinal tract, bones, reproductive organs and our immune system.
Adrenal tumors can cause either the over-production or under-production of vital hormones. Tumors that cause an over-production of hormones are called functioning tumors. Non-functioning tumors do not produce hormones. Most adrenal tumors are not inherited, but some adrenaline producing tumors and some tumors of the cortex may be the result of a genetic mutation carried through the family. A blood test can determine if genetics plays a part.
Adrenal cancer is rare (1 in a million). Most adrenal tumors are not cancerous, and may not even require any treatment. However, the long-term effects of over-production of some adrenal gland hormones can lead to severe conditions, such as heart attack and stroke, so diagnosis is important.
The most common type of adrenal tumors, called adenomas, are non-functioning and non-cancerous tumors of the adrenal cortex. Although non-cancerous, they can over-produce hormones and lead to high blood pressure, low potassium levels, headaches, sweating, palpitations and abdominal obesity (Cushing’s Syndrome). Therefore, treatment ranging from pharmaceutical therapy to surgery may be needed to prevent more serious conditions.
Adrenocortical carcinoma, though very rare, are cancerous and aggressive tumors of the adrenal cortex. It is most common in children under the age of 10 and in adults between the ages of 50 and 60. Over-production of hormone due to this type of tumor may lead to high blood pressure, weight gain and diabetes. Unfortunately, most adults may not present with symptoms at all, making diagnosis challenging.
While it’s true that many patients do not have any symptoms associated with adrenocortical tumors, changes in general health can offer important clues. Increasing blood pressure, unexplained weight gain and even the development of diabetes may point to these kinds of tumors.
Depending on the disease, simple blood and urine tests can sometimes detect the presence of excessive adrenal hormones, indicating a potential tumor. If a tumor is detected, CT scans, MRIs and nuclear medicine scans, as well as radiological testing can help pinpoint masses.
Many adrenal tumors are now found incidentally during radiologic tests being performed for other reasons (CT scans, PET scans and ultrasound).
Surgery is the best way to cure adrenal cancer. Advances in laparoscopic surgery enable us to more easily and successfully remove an adrenal gland or tumor. Three-to-four small incisions (each just one-half to one inch in length) are all that is needed to remove the mass. This approach shortens hospital stays, speeds recovery and reduces the possibility of long-term complications due to surgery. At times, especially if dealing with cancer of the adrenal, a more traditional open surgery is performed.
Here at Vanderbilt, we were one of the first in the country to remove adrenal tumors from the back, avoiding surgery in the abdominal area. See story on our posterior retroperitoneoscopic surgery.
Patients with adrenocortical carcinoma may receive radiation or chemotherapy following surgery to reduce the risk of recurrence.
Pheochromocytomas are rare, slow growing tumors in the adrenal gland that over-produce adrenaline. Because adrenaline controls our natural “fight or flight response,” over-production of this hormone can lead to high blood pressure, headaches, sweating and heart palpitations.
Biochemical tests are performed to assess the level of adrenaline and related hormones in blood and/or urine. If levels are high, a CAT scan or MRI should be performed to locate the tumor. Other tests that might be used include nuclear medicine tests such as MIBG scans and PET scans.
Though the tumor may not be cancerous, too much adrenaline can cause serious health conditions, including heart attack and stroke, which is why it is critically important to surgically remove these tumors once detected.Laparoscopic approaches (3 or 4 small incisions) are commonly used in most patients. Some patients, especially those with large tumors, may require open surgery.
Paragangliomas are rare tumors that develop in nerves outside the brain and spinal cord. They can be found anywhere along the body’s major arteries, but are most commonly found in the abdomen. Like pheochromocytomas, paragangliomas are tumors that over-produce adrenaline, so similar symptoms and serious health conditions present, including heart attack and stroke.
But unlike pheochromocytomas, paragangliomas have a higher incidence of malignancy – as high as 40 to 50% in some studies. Patients with pheochromocytomas and paragangliomas may have a genetic condition that can be passed down to their offspring, leading to formation of the same tumors.
Because over-production of adrenaline can lead to heart attack and stroke, it is very important to surgically remove these tumors once detected.
First, the pancreas is a gland beneath the stomach that performs both exocrine and endocrine functions. It secretes enzymes for the digestion of food (exocrine), and it secretes hormones for important body functions (endocrine).
Pancreatic neuroendocrine tumors, or NETs, can be functional or non-functional. Functional tumors in the pancreas over-produce pancreatic hormones, such as gastrin, insulin, glucagon and somatostatin, and are named accordingly. Therefore, tumors that over-secrete insulin are called insulinoma; gastrin – gastrinoma.
But some pancreas tumors are non-functional, meaning they do not over-produce pancreatic hormones. Although they do not produce symptoms related to changes in hormones, they can still grown and cause problems.
Both functional and non-functional tumors may be associated with other tumors in the endocrine system. They are known as MEN syndrome or Multiple Endocrine Neoplasia.
Not all neuroendocrine tumors are cancerous. However, because these tumors over-secrete essential hormones, other serious conditions, such as diabetes can result and require medical/surgical treatment. There is currently no way to know which pancreatic NETs are cancerous without removing the tumor itself and looking at it under a microscope.
Non-functional NETs are more rapidly growing and are more likely malignant than functional pancreatic neuroendocrine tumors, but more research must be done in this area.
Symptoms of functional pancreatic tumors often mirror the symptoms of the body function the hormone is attempting to regulate. As an example, insulinoma or a pancreatic tumor that over-secretes insulin, may leave patients with symptoms of very low blood sugar – blurred vision, weakness, hunger, palpitations and seizures. Likewise, tumors over-secreting gastrin can cause abdominal pain, ulcers and diarrhea because of an increase in stomach acid.
Patients with non-functional pancreatic neuroendocrine tumors often present with abdominal pain, weight loss or jaundice. Unfortunately, these symptoms may not occur until the tumor has become large.
Some patients may have the pancreatic neuroendocrine tumor discovered incidentally during a CT scan being done for other reasons.
Pancreatic neuroendocrine tumors can be quite small, but they can often be detected using ultrasound and CT scans. Blood tests evaluating the various levels of pancreatic hormones in the body can be used to detect some functional tumors, as well as provide follow-up response to surgery or medicines.
Depending on the size, location and malignancy of the tumors, surgery is often the best course of action in treating these tumors. If the tumors are functional, surgery may be followed by medical therapies to reduce over-secretion of hormones that can give rise to uncomfortable or even serious symptoms.