Unfortunately, by the time the anaplastic thyroid cancer symptoms present, many patients already have evidence that the anaplastic thyroid cancer has spread to distant sites in the body. The diagnosis of anaplastic thyroid cancer is most commonly associated with a presenting symptom of a rapidly developing or growing neck mass. These cancers grow so very rapidly that you may notice that the mass appearing to be growing even on a daily basis. The diagnosis of an anaplastic thyroid cancer neck mass is usually very large and hard even on self examination.
The diagnosis of anaplastic thyroid cancer may be also associated with a change in the quality of your voice or ability to swallow. This is because the diagnosis of anaplastic thyroid cancer is often associated with growth of the cancer into the structures around the thyroid gland. This may include the nerves that control voice box function, the esophagus, trachea (breathing tube) or even the great blood vessels of the neck (carotid artery and internal jugular vein). Over 25% of patients with a diagnosis of anaplastic thyroid cancer will be noted to have a paralyzed vocal cord or direct growth of the cancer into their trachea when first examined. The diagnosis of anaplastic thyroid cancer is commonly associated with spread to distant sites of the body in over 50% of patients on their initial presentation.
There is no such thing as an early diagnosis of anaplastic thyroid cancer. In fact, in our section of staging of anaplastic thyroid cancer you will see that the AJCC staging system begins at T4 (the most advanced T stage). What you need to know is the following. Do not delay or postpone evaluation of anaplastic thyroid cancer. Independent if you are young or advanced years, get immediate expert help!! Every single day counts. You must be promptly seen, comprehensively evaluated for the potential of a surgery by a true expert thyroid cancer surgeon. Delay in diagnosis of an anaplastic thyroid cancer or an incomplete surgery is not correctable or reversible. It may even mean the difference between curable and life-ending. Expert rapid and complete thyroid cancer surgery is the only opportunity for curing this most often deadly cancer.
If you have a needle biopsy that suggests an anaplastic thyroid cancer, then identifying an expert in thyroid cancer surgery is the most important next step! Do not delay! Anyone that asks you to wait several weeks does not understand anaplastic thyroid cancer! You will require a very intensive but also rapid evaluation before a surgical procedure would even be considered. This evaluation must include the following:
- 1) Ultrasound of the neck with possible biopsies (to understand what is the extent of cancer in your neck)
- 2) CT scan of the neck (to determine whether the anaplastic thyroid cancer can be meaningfully removed completely!)
- 3) PET/CT of the entire body (to determine whether the anaplastic thyroid cancer has spread to sites of the body outside of the neck)
- 4) MRI of the brain (to determine whether the anaplastic thyroid cancer has spread to the brain)
- 5) Comprehensive blood analysis (to determine your blood count, kidney function, liver function, thyroid function and general body chemistries)
Anaplastic thyroid cancer patients commonly present with a symptom of a rapidly increasing neck mass. Other symptoms which occur commonly with the diagnosis of anaplastic thyroid cancer include changes in the quality of their voice, difficulty swallowing or breathing, and pain or tenderness in or around the neck or ear. Less common but more advanced findings may include coughing up or spitting up blood. Any diagnosis of anaplastic thyroid cancer associated with change in voice, swallowing, difficulty breathing or pain are very serious symptoms and require prompt and thorough evaluation.
Diagnosis of Anaplastic thyroid cancer: What other tumors may also appear similar fine needle aspiration analysis (this is called a differential diagnosis)?
- Poorly differentiated thyroid cancer (This is a very aggressive cancer too. Sometimes anaplastic thyroid cancers may be called poorly differentiated thyroid cancer based upon the fine needle aspiration cytology [the way it looks under the microscope]) The evaluation, treatment approaches, and considerations are as for anaplastic thyroid cancer.
- Thyroid lymphoma (this is only a surgical disease to produce the diagnosis. Surgery is for diagnosis only. Surgery is not the treatment for thyroid lymphoma)
- Squamous cell carcinoma of the thyroid ( I have never seen)
- Sarcoma of the thyroid (I have seen only one)
- Metastatic high grade carcinoma to the thyroid (the thyroid can be a site where cancers spread to instead of beginning in the thyroid).
What are the differences between Anaplastic thyroid cancer and Papillary Thyroid Cancer?
- Anaplastic thyroid cancers are a much rarer thyroid malignancies
- Anaplastic thyroid cancers more commonly spread to neck lymph nodes (90% for anaplastic and less than 50% for papillary)
- Anaplastic thyroid cancers have a higher risk of spread to distant sites in the body ( anaplastic thyroid cancer >50% on initial presentation, papillary thyroid cancer <3%)
- Anaplastic thyroid cancers rarely produce the marker of thyroid cancers, thyroglobulin)
- Anaplastic thyroid cancers tend to occur in later decades of life (papillary thyroid cancer peak incidence 30-40 years of age)
- Anaplastic thyroid cancer effects men much more commonly than women (papillary thyroid cancer effects women more commonly than men 3:1)
- Anaplastic thyroid cancers are often and quickly lethal with greater than 90% of those afflicted succumbing to disease within one year
- If anaplastic thyroid cancers, if completely resectable, are treated post-operatively with simultaneous chemotherapy and radiation therapy. (papillary thyroid cancer rarely requires even external beam radiation therapy)
Studies-Scans-Xrays For Diagnosis of Anaplastic Thyroid Cancer
- Complete Medical History and Physical Examination
- High resolution ultrasound of the neck with fine needle aspiration biopsy to determine extent of disease)
- Scans and X-rays
- Ultrasound of necks and thyroid
- CT scan of neck
- MRI scan of brain
- PET/CT scan
- Blood Tests
- T3 and T4
- Thyroglobulin Antibody
- Complete blood count
- BUN and creatinine to determine kidney function
- Liver function tests
- Laryngoscopy (looking at the voice box)
Medical history and physical examination is required for all patients with a potential diagnosis of anaplastic thyroid cancer
If there has been a FNA and a anaplastic thyroid cancer has been suggested, a diagnosis of anaplastic thyroid cancer is possible therefore your health care professional will want to know your complete medical history. You will be asked questions about your possible risk factors, symptoms, and any other health problems or concerns.
Your doctor will examine you to get more information about possible signs of thyroid cancer and other health problems. During the exam, the doctor will pay special attention to the size and firmness of your thyroid and any enlarged lymph nodes in your neck. Examination of your voice box is part of the physical examination obtained by the surgeon for any thyroid lump. This is called a laryngoscopy and utilizes a small lighted instrument with a camera on the end to visualize the voice box . It is a simple examination obtained without the need for sedation or discomfort to examine the vocal cords and their function.
How is the Diagnosis of Anaplastic thyroid cancer Made?
- The diagnosis of anaplastic thyroid cancer can usually be made with an ultrasound guided small sampling of cells within the thyroid gland (The process of obtaining this small sampling of cells is called fine needle aspiration (FNA) cytology)
- In almost 90% of circumstances, abnormal lymph nodes will be seen in anaplastic thyroid cancer and FNA of those lymph nodes will determine the extent of neck disease. Expert ultrasound is absolutely necessary with needle biopsy confirmation.
- The diagnosis of anaplastic thyroid cancer is highly suggested when distant spread of disease is suggested in lung, bone, liver or any other site.
- The first step leading to a diagnosis of anaplastic thyroid cancer requires obtaining a small sampling of cells with a skinny needle. This is called fine needle aspiration (FNA) cytology
- o This type of biopsy can usually be done in your doctor’s office or clinic.
- o Before the biopsy, local anesthesia (numbing medicine) may be injected into the skin over the thyroid nodule.
- o Your doctor will place a thin, hollow needle directly into the nodule to aspirate (take out) some cells and possibly a few drops of fluid into a syringe.
- o The doctor usually repeats this 2 or 3 more times, taking samples from several areas of the nodule.
- o The content of the needle and syringe are then placed on a glass slide and then the FNA samples are then sent to a lab, where they are looked at under a microscope by the expert Cytologist to see if the cells look cancerous or benign.
- Cytology means looking at just the cells under the microscope.
- Thyroid cytology requires an expert physician (called a Cytologist) trained specifically in the diagnosis of anaplastic thyroid cancer!!!
- Bleeding at the biopsy site is very rare except in people with bleeding disorders. Even when this occurs, the bleeding is almost always very self limited. Be sure to tell your doctor if you have problems with bleeding or are taking medicines that could affect bleeding, such as aspirin or blood thinners.
- Sometimes an FNA biopsy will need to be repeated because the samples didn’t contain enough cells.
- If the mass is quite large, sometimes a cell sampling can be difficult because of necrosis (dead cells) in the center. In these instances, numbing medication and a slightly larger piece of the tumor is biopsied with a larger needle type instrument. This is called a core biopsy.
- Rarely, the FNA biopsy may come back inconclusive (not diagnostic) even though anaplastic thyroid cancer is present. Your doctor must be knowledgeable regarding this possibility.
Concern Over A Diagnosis of Anaplastic thyroid cancer: What If The Diagnosis is Not Clear?
Most of the time, FNA results from an anaplastic thyroid cancer (carcinoma) will be interpreted as one of the following:
- Anaplastic thyroid cancer
- Poorly differentiated thyroid cancer
- Thyroid cancer with “high grade” features
- Thyroid cancer with large cell features
- Thyroid cancer with squamous differentiation
- Thyroid cancer with sarcomatoid features
The meaning of the above descriptions is really solely important in that they are all saying the same thing!!! This is a really aggressive cancer. Do not delay. Do not underestimate the cancer. Look promptly and thoroughly to determine the extent of the cancer. Find an expert.
If this happens, some doctors may order tests on the sample to look at special markers on the surface of the cells to determine if this is anaplastic thyroid cancer or cancer that may have begun someplace else and then spread to the thyroid gland. Other tests may be ordered by doctors as well to see if there are genetic abnormalities noted (changed). With the tremendous advances in science and medicine over the past several years, rapid delivery of genetic information can be obtained. The important question is to ask the question “How will this information change my approach to my anaplastic thyroid cancer?”
For example, if you have a large mass in your thyroid and the fine needle biopsy has revealed anaplastic thyroid cancer but your prompt evaluation of your body for distant spread of cancer shows that your neck is the only site of disease, then your only chance of surviving your cancer (to mine and everyone else’s knowledge, is to have complete removal of your anaplastic thyroid cancer and then very prompt completion of both chemotherapy and radiation therapy to your neck and upper chest area.
I received a phone call from a referring endocrinologist in California on a Thursday afternoon. A 71 year old woman presents to him with a rapidly developing left thyroid mass and hoarseness. The thyroid mass was minimally moveable in her neck but was painless. She was otherwise a healthy woman. Her endocrinologist performed a needle biopsy and his suspicion was this was an anaplastic thyroid cancer. The referring endocrinologist asked if I could see her promptly or whether she should undergo further testing at home before she traveled to see me. We jointly decided that I would see her as soon as she could arrive.
Three days later, E.M. arrived and the following CT scan was obtained.
A large right anaplastic thyroid cancer is shown with red arrow (CAT scan shows a mirror image). The cancer is growing into the breathing tube (trachea) yellow arrow. The esophagus cannot be distinguished from the anaplastic thyroid cancer (the cancer has grown into the swallowing tube).
E.M. undergoes the following tests (MRI brain, CT chest, and PET/CT scan) and all reveal no evidence of spread to any other sites.
Four days following the referring phone call, E. M. undergoes an extensive surgery to remove all of her anaplastic thyroid cancer from her neck. Although her left true vocal cord to her voice box was paralyzed prior to her surgery, E.M. leaves the hospital 24 hours following her surgery.
M. begins her simultaneous chemotherapy and radiation therapy to her neck seven days following her surgery and completes her six and a half weeks of radiation as prescribed.
The following is her testimonial (M. 67 year old woman, San Jose CA)
“I was diagnosed with a rapidly expanding thyroid cancer that had paralyzed half of my voice box. It was needle biopsied and found to be one of the worst cancers known to occur in people, called anaplastic thyroid cancer.
Dr. Clayman was smart about my problem, quick to act, informative every step of the way, with a caring, thoughtful manner. He played a critical role in saving my life, so he's got to be doing something right. That was seven years ago now. I was cured of an incurable cancer!
My referring doctor hopes Dr. Clayman will continue practicing for a long time to come because she very much wants to continue referring all of her patients to him. We couldn't have made a better choice.”
This picture is of E.M.’s neck eight years after right extended neck dissection, total thyroidectomy and post operative chemotherapy and radiation therapy for anaplastic thyroid cancer. She is happy and living a full life. The prominent red marks on her skin are the long term result of chemotherapy and radiation therapy to the skin and deeper tissues.
This is not the usual outcome but it is a potential outcome with prompt diagnosis and appropriate therapy!
In October 2004, 3 weeks after his 80th birthday, Chief Justice William Rehnquist was diagnosed with anaplastic thyroid cancer. It was not announced for a number of weeks what type of thyroid cancer he had—only that he had thyroid cancer.
But his case is classic for anaplastic thyroid cancer. He received some of the best medical care in the world, including annual physical exams. The mass in his neck was rapidly growing and obviously was not present a year earlier—this is very typical of anaplastic thyroid cancer. He was in the correct age group for being diagnosed with anaplastic cancer and of course, he was a man.
The very day of his diagnosis, he underwent a tracheostomy, a procedure that is typical of patients with anaplastic thyroid cancer which establishes the ability to breath around the cancer (and extremely rare for the other types of thyroid cancer). He immediately began external-beam radiation therapy (again, classic for anaplastic thyroid cancer and very rarely used for the typical papillary or follicular thyroid cancers). He also began chemotherapy treatments, which are essentially never used for papillary, follicular, and hurthle cell thyroid cancers.
On Thursday, January 20, 2005, Chief Justice Rehnquist swore in George W. Bush as President of the United States for his second term. The Chief Justice appeared to be doing very well, but he had a tough road in front of him.
On Saturday, September 3, 2005, Chief Justice Rehnquist died in his home at the age of 80. Sadly, his case is typical of anaplastic thyroid cancer. He died of a disease that was diagnosed less than 11 months earlier. Not all people with anaplastic thyroid cancer die, but it is extremely important that this disease is caught early and treated aggressively.
What is the Role of Genetic Analysis of Anaplastic Thyroid Cancers?
Several years ago, even though we could easily perform genetic analysis to determine which genes were abnormal in anaplastic thyroid cancer, this information would have been of little value to the patient. Today, we clearly know that although the usual thyroid cancers such as papillary and follicular thyroid cancers have relatively few gene mutations, anaplastic thyroid cancers have many more mutations. Although much still has to be learned, the genetic mutations of BRAF, TERT, pI3kinase, and p53 tend to occur commonly in the more aggressive thyroid cancers such as anaplastic thyroid cancer especially the last three listed. More so, if anaplastic thyroid cancer patients have or develop distant spread of their cancers, genetic analysis may have a role in selecting which therapy is best suited to address this grave disease. This has been termed personalized targeted therapy.
If the diagnosis of anaplastic thyroid cancer has been rendered and your comprehensive evaluation for distant spread of your cancer is negative, you must be in the care of only the most expert of thyroid cancer surgeons. Surgery for anaplastic thyroid cancer is the most difficult thyroid cancer surgery known to man. It should never be assessed or performed by an inexperienced thyroid cancer surgeon. Anaplastic thyroid cancer is rarely if every multifocal. What this means is that there is little to no risk that the anaplastic thyroid cancer will be found in multiple distinct locations in a thyroid gland. The exact extent of the surgery is dependent upon how extensive the anaplastic thyroid cancer has grown and spread within the neck. This is determined by putting together all the information from the high resolution ultrasound, CT scan of the neck, PET/CT scan and the findings of the surgeon during the surgery itself. Anaplastic thyroid cancer can grow so quickly that literally the findings on all of these imaging studies can change within days!!!
Total thyroidectomy is generally the preferred treatment for patients with a diagnosis of anaplastic thyroid cancer. In some circumstances, a less than total thyroidectomy may be recommended for the surgical procedure for anaplastic thyroid cancer. I would consider a less than total thyroidectomy under the following circumstances (all would likely be necessarily):
- The recurrent laryngeal nerve on the side of the cancer is already paralyzed by the anaplastic thyroid cancer.
- The remaining thyroid lobe has no abnormalities in it whatsoever.
- The central compartment lymph nodes on the side opposite of the anaplastic thyroid cancer are not involved with cancer.
- The trachea (breathing tube) is not invaded by the anaplastic thyroid cancer
Anaplastic thyroid cancer exquisitely rarely occurs in more than one site of the thyroid gland! (I have never seen it!)
FNA might not be the first test done if you have a suspicious lump in your neck for anaplastic thyroid cancer. The doctor might order other tests first, such as blood tests and an ultrasound exam to get a better sense of whether you might have a diagnosis of anaplastic thyroid cancer. These tests are described following this section.
What Imaging Tests Are Used For A Diagnosis of Anaplastic Thyroid Cancer?
Imaging tests may be done for a number of reasons, including to help find suspicious areas that might be cancer, to learn how far cancer may have spread, and to help determine the extent of surgery and the role of other treatments or therapies.
People who have or may have a diagnosis of anaplastic thyroid cancer will get one or more of the following tests:
Ultrasound uses sound waves to create pictures inside your neck. The thyroid ultrasound must not only examine the thyroid gland but also must include a comprehensive examination of your neck lymph nodes. For this test, a small, wand-like instrument called a transducer is placed on the skin in front of your thyroid gland and all levels of the neck. It gives off sound waves and picks up the echoes as they bounce off the thyroid (and other underlying neck structures). The echoes are converted by a computer into a black and white image on a computer screen. You are not exposed to any radiation during this test.
A high resolution ultrasound machine for evaluation of the thyroid and neck.
This test can help determine if a thyroid nodule is solid or filled with fluid. (Solid nodules are more likely to be cancerous.) It can also be used to check the number and size of thyroid nodules. Further, it can even reveal what the blood supply looks like to these nodules. How a nodule looks on ultrasound can sometimes suggest if it is likely to be a cancer, but ultrasound can’t tell for sure. Importantly, a cystic nodule is most commonly benign (not cancer). A cystic nodule does not look the same as a necrotic nodule on ultrasound. A large mass of the thyroid with abnormal blood vessels and necrosis and debris in its center is very worrisome on ultrasound for a diagnosis of anaplastic thyroid cancer. Frequently the ultrasound will show local invasion of the thyroid mass into muscles, trachea or esophagus, as well as abnormal lymph nodes around the thyroid gland.
Ultrasound of the thyroid gland. The yellow arrow points to an 8 cm mass within the right thyroid. For most thyroid nodules, ultrasound is used to guide a biopsy needle into the thyroid nodule to obtain a confident sampling of the cells within it. This is an anaplastic thyroid cancer and the ultrasound is used to make sure that the needle is within a portion of solid tumor since much of the tumor becomes necrotic because the mass is growing so quickly that it can outgrow its own blood supply.
Complete examination of neck lymph nodes is required for every thyroid mass examination and especially any anaplastic thyroid cancer. The expert ultrasonographer will look for multiple changes. Although many unskilled observers would believe that size is a major issue, but in fact it is not. High resolution ultrasound can detect a diagnosis of spread of thyroid cancer to lymph nodes as small as 1-2 mm (the size of a tip of a ball point pen). Sometimes simultaneous thyroid tumors can occur simultaneously together such as an anaplastic thyroid cancer and a papillary thyroid cancer. These two cancers may be totally unrelated to each other. Thus abnormal lymph nodes may be present and require FNA. When looking at the lymph nodes in the neck with ultrasound, the following are important criteria which may lead to a FNA needle biopsy to confirm disease.
- Full of rounded lymph nodes
- Displacement or disruption of the normal ultrasonic “architecture” of a lymph node
- Cystic lymph nodes
- Microcalcifications within lymph nodes (small ultrasonic calcifications)
- Disorganized vascular flow to the lymph node
- Larger or asymmetric lymph nodes when comparing one side of the neck to the other
The quality of the ultrasound is dependent upon four factors. Each factor is critically important. The least quality of any factor produces the ultimate quality of the ultrasound. It is dependent upon:
- The quality of the ultrasound machine
- The device that is held in the hand of the technician (the transducer) producing the sound waves
- The experience and the skill of the ultrasound technician
- The experience of the radiologist or diagnostician who is interpreting the study.
We perform an ultrasound on all of our patients ourselves because we have learned that ultrasounds performed elsewhere are not as accurate as we need. The most highly skilled ultrasound will detect abnormalities within lymph nodes within 2 mm. This is approximately the size of a ball point pen head. Your ultrasound should be performed by someone who is specifically dedicated to the ultrasound examination of the thyroid and neck. Experience means everything when you are considering the sensitivity of neck ultrasound.
The ultrasound study will always critically look not only at the thyroid but all the tissues in your neck. The ultrasound can show whether something is cystic or solid. It can see the blood supply to a particular area. It can reveal microscopic calcifications that may indicate a cancer. Ultimately, your ultrasound will determine whether a biopsy with a tiny needle is indicated or whether a simple blood test may only be indicated. Even if you have already had a biopsy, another biopsy may be indicated if:
- The first biopsy did not provide a diagnosis
- The ultrasound shows something that was previously not seen.
Computed tomography (CT) scan for Anaplastic thyroid cancer
The CT scan of the neck for anaplastic thyroid cancer is an x-ray test that produces detailed cross-sectional images of your body from the bottom of your brain to the middle of your chest. It can help determine the location and size of the anaplastic thyroid cancer, whether the cancer has invaded into any nearby structures, and whether they have spread to lymph nodes in nearby areas. A CT scan can also be used to look for spread into distant organs such as the lungs.
A CT scan of the neck is absolutely required for a suspicion or diagnosis of anaplastic thyroid cancer. This test needs to be done with contrast. Without the use of iodinated intravenous contrast, this study is essentially useless.
Even if the diagnosis of anaplastic thyroid cancer has not been arrived upon, the following are indications for obtaining a CT scan of the neck (masses high risk for a diagnosis of anaplastic thyroid cancer) include:
- Large thyroid nodule more than 4 centimeters which is suspicious for a high grade malignancy
- Fixed or minimally mobile mass
- Ultrasound suggesting soft tissue extension or invasion
- Patient presenting with symptoms of:
- Vocal cord paralysis
- Difficulty swallowing
A CT scanner has been described as a large donut, with a narrow table in the middle opening. You will need to lie still on the table while the scan is being done. CT scans take longer than regular x-rays, and you might feel a bit confined by the ring while the pictures are being taken.
Instead of taking one picture, like a regular x-ray, a CT scanner takes many pictures while you lie on the table. A computer then combines these pictures into images of slices of the part of your body being studied. A CT scan designed for a diagnosis of anaplastic thyroid cancer is sliced at 1mm steps. It is an incredibly detailed study that creates very exquisite images.
Before the test, you will be asked to receive an IV (intravenous) line through which a contrast dye is delivered. This helps better outline structures in your body. The injection may cause some flushing (a feeling of warmth, especially in the face). Some people are allergic and get hives. Rarely, more serious reactions like trouble breathing or low blood pressure can occur. Be sure to tell the doctor if you have any allergies or have ever had a reaction to any contrast material used for x-rays.
You may have heard of a theoretical problem with using CT scans for a diagnosis of anaplastic thyroid cancer because the CT contrast dye contains iodine, which interferes with radioiodine scans. This should not be a consideration whatsoever. Radioactive iodine plays little to no role in the management of anaplastic thyroid cancer. Get the CT scan, don’t worry about radioactive iodine.
The CT scan for the potential diagnosis of anaplastic thyroid cancer provides different information to your doctor than the ultrasound. The ultrasound tells the doctor if there is something abnormal. The CT scan tells the doctor where the abnormality is located and what structures may be involved! Both studies complement each other. The CT scan of the neck also can look at areas of the neck that the ultrasound cannot study because sounds waves cannot pass effectively through bone, cartilage or air. Specifically, the CT scan can effectively see behind the jaw bone (mandible), collar bone (clavicle) or chest wall and also behind the voice box (larynx), breathing tube (trachea), and swallowing tube (esophagus). In all of these sites, the ultrasound examination can be quite limited and therefore a CT scan may provide valuable additional information regarding the extent of the anaplastic thyroid cancer and what structures it involves. Ultimately, all of these studies will determine the extent of required surgery.
The above xray is a picture of one slice of a CT scan of an anaplastic thyroid cancer patient. The blue arrow shows the anaplastic thyroid cancer beginning to grow into the trachea (breathing tube). This cancer was removed and the patient treated immediately after surgery with radiation and chemotherapy. She is alive and well seven years following her surgery.
In patients with a diagnosis of anaplastic thyroid cancer, a CT scan of the chest should be obtained. The CT scan of the chest provides an excellent baseline examination (for following) of the lungs, the highest risk site for distant spread in patients with a diagnosis of anaplastic thyroid cancer.
Magnetic resonance imaging (MRI) scan
Like CT scans, MRI scans can be used to look at a presumed diagnosis of anaplastic thyroid cancer, or cancer that has spread to nearby or distant parts of the body. But ultrasound is usually the first choice for looking at the thyroid and neck structures. MRI scans are particularly helpful in looking at the brain and spinal cord.
MRI scans use radio waves and strong magnets instead of x-rays, therefore there is no radiation exposure. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into a very detailed image of parts of the body. A contrast material called gadolinium is often injected into a vein before the scan to better show details.
MRI scans take longer than CT scans – often up to an hour. You may have to lie inside a narrow tube, which can upset people with a fear of enclosed spaces. Newer, more open MRI machines can sometimes be used instead. The machine also makes buzzing and clicking noises, so some centers provide earplugs to block this noise out.
MRI scans are very sensitive to movement and moving during the scanning process produces artifacts that make interpretation difficult. Because people are constantly swallowing and unconsciously moving their voice box and swallowing structures (and therefore their thyroid gland and surrounding lymph nodes, CT of the neck is the preferred cross sectional study of the neck in patients with a suspicion for a diagnosis of anaplastic thyroid cancer.
Anaplastic thyroid cancer can spread to the brain and may occur in 10-20% of anaplastic thyroid cancers with distant spread of their cancer. An MRI of the brain is indicated in the diagnostic evaluation of patients with anaplastic thyroid cancer.
Positron emission tomography (PET)/CT scan
For a PET scan, a radioactive substance (usually a type of sugar related to glucose, known as FDG) is injected into the blood. The amount of radioactivity used is very low. Because cancer cells in the body generally utilize sugar as their energy source to grow, they absorb more of the sugar than normal cells. After waiting about an hour, you lie on a table in the PET scanner for about 30 minutes while a special camera creates a picture of areas of radioactivity in the body.
The PET/CT scan for a diagnosis of anaplastic thyroid cancer combines images of both a PET and CT scan at the same time. The cells in the body that are using the glucose “light up” on the PET scan. However, PET images alone are not very detailed. The computer shows the relative amount of radioactivity to a particular area and where the sugar is localized and it appears red or “hot”. The combination of these two images lets the doctor compare an abnormal area on the PET scan with its detailed appearance and location on the CT scan. The CT scan when combined with the PET scan shows your doctor exactly where the cancerous activity is located in the body.
This test is an incredibly valuable diagnostic tool in patients with anaplastic thyroid cancer since it scans essentially the entire body looking for the potential of distant spread of the anaplastic thyroid cancer.
- It is commonly used in the upfront evaluation of patients with anaplastic thyroid cancer in the analysis of distant metastases
- It is commonly used in the follow-up evaluations of patients with anaplastic thyroid cancer for the analysis of distant metastases.
PET/CT scanning is commonly positive in patients with a diagnosis of anaplastic thyroid cancer. These images are PET scans of a 59 year old man who developed a rapidly growing thyroid mass and hoarseness. The yellow arrow points to a very “bright” left thyroid mass (right and left are mirror images on xrays) which is anaplastic thyroid cancer. The redish arrows (above) point to several representative areas where the anaplastic thyroid cancer has already spread to distant areas in the body.
- The initial evaluation of a Dedifferentiated or poorly differentiated anaplastic thyroid cancer patient
- Follow-up evaluations of a dedifferentiated or poorly differentiated anaplastic thyroid cancer
Blood tests alone cannot tell the extent of a diagnosis of anaplastic thyroid cancer. Blood tests are a tool used with other studies, to monitor the adequacy of your thyroid hormone levels produced by your thyroid or by the intake of prescription thyroid hormones.
Thyroid cells and follicular thyroid cancers also produce a protein called thyroglobulin which can be used as a blood monitoring tool in most differentiated thyroid cancer patients (papillary and follicular thyroid cancers). Often times anaplastic thyroid cancers will not produce significant amounts of thyroglobulin whatsoever.
Thyroid-stimulating hormone (TSH)
Tests of blood levels of thyroid-stimulating hormone (TSH or thyrotropin) may be used to check the overall activity of your thyroid gland or how much thyroid hormone pill your body requires. Levels of TSH, which is made by a gland in the brain called the pituitary gland, may be high if you do not have enough thyroid hormone in your body. In previously untreated patients with a potential diagnosis of anaplastic thyroid cancer, their TSH level is usually normal. In some patients with poorly differentiated thyroid cancers that are being evaluated for radioactive iodine treatment, they are most commonly taken off of thyroid hormone and their doctor will measure their TSH level which should be markedly elevated (radioiodine scans require the body to be hypothyroid). Alternatively, a medicine called Thyrogen (which is TSH produced as a drug) can also be given to patients with a diagnosis of thyroid cancer by injection to make the body “appear” to be hypothyroid. After patients with a diagnosis of anaplastic thyroid cancer have undergone their surgery, their endocrinologist will likely want to keep their TSH level low to prevent stimulation of your thyroid gland and the potential stimulation of undetectable microscopic anaplastic thyroid cancer cells.
T3 and T4 (thyroid hormones)
These are the main hormones made by the thyroid gland. Levels of these hormones may also be measured to get a sense of overall thyroid gland function. The T3 and T4 levels are usually normal in patients with a previously untreated diagnosis of anaplastic thyroid cancer. Anaplastic thyroid cancer rarely produces produces either T3 or T4 hormones. Interesting, even in patients with a potential diagnosis of anaplastic thyroid cancers that are quite massive with very little normal appearing thyroid tissue, hypothyroidism is quite infrequent as well.
Thyroglobulin is a protein made by the thyroid gland that can be measured in blood sampling. Measuring the thyroglobulin level in the blood can’t be used to make a diagnosis of anaplastic thyroid cancer. Most commonly, anaplastic thyroid cancer does not produce detectable amounts of thyroglobulin.
Other blood tests
You might have other blood tests as well. For example, if you are scheduled for thyroid surgery, tests will be done to check your blood cell counts, to look for bleeding disorders, and to check the function of your liver and kidneys.
Vocal cord exam (laryngoscopy)
Thyroid tumors can sometimes affect the function of your voice box. Even if your voice sounds normal to you and others, this does not mean that your vocal cords are functioning normally. If you are going to undergo a surgery for a diagnosis of anaplastic thyroid cancer, a procedure called a laryngoscopy will probably be done first to see if the vocal cords are moving normally. For this exam, the doctor looks through the nose or down the throat at the larynx (voice box) with a special thin tube with a light and a lens on the end for looking at the voice box. This special tiny scope is inserted through the nose and there is little to no discomfort associated with the examination.
If you are being considered for surgery with a diagnosis of anaplastic thyroid cancer, it is very common for one of the nerves to the voice box to be involved directly by growth of the cancer. The risk of hoarseness due to invasion of the anaplastic thyroid cancer into the nerve of the voice box is often associated with a diagnosis of anaplastic thyroid cancer.
For the Potential Diagnosis of Anaplastic thyroid cancer: The Best Treatment is a Great Surgery-if feasible!
The diagnosis of anaplastic thyroid cancer (carcinoma) is only able to be cured and patients offered the potential for long term control when a “cancer appropriate” surgery which results in complete removal of all visible, radiographic and palpable anaplastic thyroid cancer is achieved. Complete removal of all visible, radiographic and palpable anaplastic thyroid cancer provides a patient with a diagnosis of anaplastic thyroid the only opportunity for long term control and cure of their cancer. In contrast, an incomplete surgery results in the likely:
- Rapid recurrence (or peristance) of the anaplastic thyroid cancer in the neck!!!
- anaplastic thyroid cancer spreading to distant sites of the body
- invasion of the anaplastic thyroid cancer into important structures in the neck
- breathing difficulty
- ultimately the inability to be cured of the anaplastic thyroid cancer.
The optimal extent of initial surgery is determined by a combination of the ultrasound and CT scan of the thyroid and neck to look closely at the thyroid gland and the lymph nodes of the neck. The section of ultrasound in the diagnosis of anaplastic thyroid cancer has a great general overview of the importance of high resolution ultrasound in the evaluation of anaplastic thyroid cancer. If there are any abnormal lymph nodes of the neck that have worrisome characteristics the next step is almost always a needle biopsy. The CT scan of the neck is used to examine whether the anaplastic thyroid cancer has invaded into adjacent structures including trachea, esophagus, muscles and blood vessels.
The Diagnosis of Anaplastic thyroid cancer Can Be Associated with Predictable Behavior
- Anaplastic thyroid cancer is rarely diagnosed with disease localized only within the neck
- Distant spread of anaplastic thyroid cancer is commonly identified on initial evaluation of patients with this disease
- The diagnosis of anaplastic thyroid cancer is commonly associated with a rapidly growing thyroid or neck mass
- Anaplastic thyroid cancers commonly grow into important structures of the neck including the trachea, esophagus, and blood vessels
- The diagnosis of anaplastic thyroid cancer is commonly rapidly fatal within one year of diagnosis.
- The diagnosis of anaplastic thyroid cancer, is a serious and frequently grave diagnosis independent of the age of the patient.
- The diagnosis of anaplastic thyroid cancer spread to distant sites of the body may occur in around 90% of patients. (One of the most lethal cancers known to mankind).
- When it does spread to other areas of the body, the lungs, then liver and then bones are the most commonly found involved locations. However, anaplastic thyroid cancer can spread to any site whatsoever.
- The diagnosis of anaplastic thyroid cancer spread to distant sites is serious and requires an interdisciplinary thyroid cancer team that is very knowledgeable about the patient and the cancer itself.
- The diagnosis of distant spread of anaplastic thyroid cancer is often rapidly fatal.
- Surgery plays little role in the management of anaplastic thyroid cancer if it has spread to distant sites.
- There is no role for radioactive iodine in the treatment of anaplastic thyroid cancer with a diagnosis of distant spread.
Diagnosis of Anaplastic Thyroid Cancers- Pathologic Types
This is a picture of a microscopic examination of an anaplastic thyroid cancer. There are multiple large and small purplish appearing cells. Multiple cells are seen undergoing division (they are dividing and multiplying rapidly).
This picture is an anaplastic thyroid cancer which has begun within an existing papillary thyroid cancer.
This picture is an anaplastic thyroid cancer with giant cells. (Large cells with big blueish nucleus in the center of the cells).
Whichever Type of Anaplastic Thyroid Cancer
- Surgery is the only opportunity for cure but is frequently not meaningful to most anaplastic thyroid cancer patients
- Distant spread of the cancer is common
- Lymph node metastases are common
- Needle biopsy many not be conclusive for diagnosis due to necrosis and other factors
- Long term survival is rare
- New therapies are being developed
- Genetic alterations may be useful in selecting medical treatment options.
Diagnosis of Anaplastic Thyroid Cancer: Risk Factors for Developing this Cancer
The diagnosis of anaplastic thyroid cancer may also be associated with the following:
- A long standing history of a lumps or nodules in the thyroid gland
- A long standing history of thyroid goiter
- A history of radiation exposure or previous radiation treatment (other than routine x rays)
- Men with advanced age
- Editorial note: The diagnosis of anaplastic thyroid cancer is not commonly associated with any risk factors. (For more information see section on Anaplastic Thyroid Cancer Genetics and Special Cases)