Thyroid Cancer Symptoms and Signs
The most common signs and symptoms of thyroid cancer include;
- A lump, or thyroid nodule that can be felt in the neck
- Trouble swallowing
- Throat or neck pain
- Swollen lymph nodes in the neck
- Vocal changes
The term "thyroid nodule" refers to any abnormal growth that forms a lump in the thyroid gland.
The thyroid gland is located low in the front of the neck, below the Adam's apple. The gland is shaped like a butterfly and wraps around the windpipe or trachea. The two wings or lobes on either side of the windpipe are joined together by a bridge of tissue, called the isthmus, which crosses over the front of the windpipe.
A thyroid nodule can occur in any part of the gland. Some nodules can be felt quite easily. Others can be hidden deep in the thyroid tissue or located very low in the gland, where they are difficult to feel.
The most common signs and symptoms of thyroid cancer include;
A goiter is simply an enlarged thyroid gland. Multiple conditions can lead to goiter, including hypothyroidism, hyperthyroidism, excessive iodine intake, or thyroid tumors. Goiter is a non-specific finding that warrants medical evaluation.
The vast majority of thyroid nodules do not cause symptoms. However, if the cells in the nodules are functioning and producing thyroid hormone on their own, the nodule may produce signs and symptoms of too much thyroid hormone (hyperthyroidism). A small number of patients complain of pain at the site of the nodule that can travel to the ear or jaw. If the nodule is very large, it can cause difficulty swallowing or shortness of breath by compressing the esophagus (tube connecting the mouth to the stomach) or trachea (windpipe). In rare instances, a patient may complain of hoarseness or difficulty speaking because of compression of the larynx (voice box).
Thyroid nodules may be single or multiple.
The cause of most thyroid nodules is unknown. In certain cases, insufficient iodine in the diet can cause the thyroid to develop nodules, but this is no longer common in the U.S. Certain genes may contribute to development of thyroid nodules.
Modern imaging techniques - such as ultrasound (US), computerized tomography (CT), and magnetic resonance imaging (MRI) - have revealed more thyroid nodules incidentally This means that nodules are being found during studies that were done for reasons other than examination of the thyroid per se. Up to 4% to 8% of adult women and 1% to 2% of adult men have thyroid nodules detectable by physical examination. Closer to 30% of adult women have nodules detectable by ultrasound. In fact, diagnosis of a thyroid nodule is the most common endocrine problem in the United States.
Although the majority of thyroid nodules are benign (not cancerous), about 10% of nodules do contain cancer. Therefore, the primary purpose for evaluating a thyroid nodule is to determine whether cancer is present.
Thyroid nodules usually are discovered by the health care professional during routine physical examination of the neck. Occasionally, a patient may notice a nodule as a small lump in their neck when looking in the mirror. Once a nodule is discovered, a physician will carefully evaluate the nodule.
History: The doctor will take a detailed history, evaluating both past and present medical problems. If the patient is younger than 20 or older than 70 years, there is increased likelihood that a nodule is cancerous. Similarly, the nodule is more likely to be cancerous if there is any history of radiation exposure, difficulty swallowing, or a change in the voice. It was actually customary to apply radiation to the head and neck in the 1950s to treat acne! Significant radiation exposures include the Chernobyl and Fukushima disasters. Although women tend to have more thyroid nodules than men, the nodules found in men are more likely to be cancerous. Despite its value, the history cannot differentiate benign from malignant nodules. Thus, many patients with risk factors uncovered in the history will have benign lesions. Others without risk factors for malignant nodules may still have thyroid cancer.
Physical examination: The physician should determine if there is one nodule or many nodules, and what the remainder of the gland feels like. The probability of cancer is higher if the nodule is fixed to the surrounding tissue (unmovable). In addition, the physical exam should search for any abnormal lymph nodes nearby that may suggest the spread of cancer. In addition to evaluating the thyroid, the physician should identify any signs of gland malfunction, such as thyroid hormone overproduction (hyperthyroidism) or underproduction (hypothyroidism).
Blood tests: Initially, blood tests should be done to assess thyroid function. These tests include:
Ultrasonography: A physician may order an ultrasound examination of the thyroid to:
Despite its value, the ultrasound cannot determine whether a nodule is benign or cancerous.
Radionuclide scanning: Radionuclide scanning with radioactive chemicals is another imaging technique a physician may use to evaluate a thyroid nodule. The normal thyroid gland accumulates iodine from the blood and uses it to make thyroid hormones. Thus, when radioactive iodine (123-iodine) is administered orally or intravenously to an individual, it accumulates in the thyroid and causes the gland to "light up" when imaged by a nuclear camera (a type of Geiger counter). The rate of accumulation gives an indication of how the thyroid gland and any nodules are functioning. A "hot spot" appears if a part of the gland or a nodule is producing too much hormone. Non-functioning or hypo-functioning nodules appear as "cold spots" on scanning. A cold or non-functioning nodule carries a higher risk of cancer than a normal or hyper-functioning nodule. Cancerous nodules are more likely to be cold, because cancer cells are immature and don't accumulate the iodine as well as normal thyroid tissue. However, cold spots can also be caused by cysts. This makes the ultrasound a much better tool for determining the need to do an FNA.
Fine needle aspiration: Fine needle aspiration (FNA) of a nodule is a type of biopsy and the most common, direct way to determine what types of cells are present. The needle used is very thin. The procedure is simple and can be done in an outpatient office, and anesthetic is injected into tissues traversed by the needle. FNA is possible if the nodule is easily felt. If the nodule is more difficult to feel, fine needle aspiration can be performed with ultrasound guidance. The needle is inserted into the thyroid or nodule to withdraw cells. Usually, several samples are taken to maximize the chance of detecting abnormal cells. These cells are examined microscopically by a pathologist to determine if cancer cells are present. The value of FNA depends upon the experience of the physician performing the FNA and the pathologist reading the specimen. Diagnoses that can be made from FNA include:
One of the most difficult problems for the pathologist is to be confident that a follicular adenoma - usually a benign nodule - is not a follicular cell carcinoma or cancer. In these cases, it is up to the physician and the patient to weigh the option of surgery on a case-by-case basis, with less reliance on the pathologist's interpretation of the biopsy. It is also important to remember that there is a small risk (3%) that a benign nodule diagnosed by FNA may still be cancerous. Thus, even benign nodules should be followed closely by the patient and physician. Another biopsy may be necessary, especially if the nodule is growing. Most thyroid cancers are not very aggressive; that is, they do not spread rapidly. The exception is poorly differentiated (anaplastic) carcinoma, which spreads rapidly and is difficult to treat.
Follicular adenomas are difficult to distinguish from follicular cancers. Follicular nodules, other nodules highly suspicious for cancer and definite cancer should be treated by surgery. Most thyroid cancers are curable and rarely cause life-threatening problems. Any nodule not removed needs to be watched closely by follow-up with the physician every 6 to 12 months. This follow-up may involve a physical examination, ultrasound examination, or both. Occasionally, a physician may attempt to shrink the nodule by using suppressive doses of thyroid hormone. Some physicians believe that if a nodule shrinks on suppressive therapy, it is more likely to be benign. Recent large studies have shown that treating with thyroid suppression does not make a difference.
If a nodule causes hyperthyroidism, it is usually noncancerous. Treatment is aimed at preventing the signs, symptoms, and complications of hyperthyroidism, such as heart failure, osteoporosis,, and rapid heart rate. Treatments include destroying the gland using radioactive iodine (131-iodine), blocking production of thyroid hormone with medications, or conservatively following the patient with mild hyperthyroidism. "Subclinical hyperthyroidism" refers to an adult patient with a hyperfunctioning nodule, but TSH is minimally suppressed and the blood levels of thyroid hormones are normal. Treatment is individualized based on age, presence of other medical conditions, and patient preference.
Hypothyroidism is any state in which thyroid hormone production is below normal. Normally, the rate of thyroid hormone production is controlled by the brain by the pituitary gland. Hypothyroidism is a very common condition and the symptoms of hypothyroidism are often subtle, but may include, constipation, memory loss, hair loss, and depression. There are a variety of causes of hypothyroidism, and treatment depends on the cause.
Thyroid blood tests determine the adequacy of the levels of thyroid hormones in in a patient. The blood tests can determine if the thyroid gland's hormone production is normal, overactive, or underactive. The level of thyroid hormones may help to diagnose hypothyroidism or hyperthyroidism. The test may also point to other diseases of conditions of the thyroid gland.
Thyroid disease and disorder symptoms and signs depend on the type of the thyroid problem. Examples include heat or cold intolerance, sweating, weight loss or gain, palpitations, fatigue, dry skin, constipation, brittle hair, joint aches and pains, heart palpitations, edema, feeling bloated, puffiness in the face, reduced menstrual flow, changes in the frequency of bowel movements and habits, high cholesterol, hoarseness, brittle hair, difficulty swallowing, shortness of breath, a visible lump or swelling in the neck, tremors, memory problems, depression, nervousness, agitation, irritability, or poor concentration.
Thyroid problems are more common in women.