Hashimoto’s disease is a member of the family of “auto-immune” diseases such as Rheumatoid arthritis. These diseases are characterized by an immune system that, for some reason, identifies the patient’s own tissue as being “foreign” or not a normal, natural part of that person’s body. A good example of this is demonstrated when a patient receives a kidney transplant and the immune system recognizes that this new tissue is, indeed, foreign. The immune system then makes antibodies to go and attack this “foreign” tissue. This results in a battle between the antibodies and the tissue perceived as foreign, and this results in inflammation. In the case of the kidney, it causes a “nephritis”. In the case of the rheumatoid arthritis patient, the joint capsule is attacked, and this causes an “arthritis”. In the thyroid it causes a “thyroiditis”.
There are other ways the thyroid gland can become inflamed and a thyroiditis results, but if the inflammation is due to the patient producing antibodies against his or her own thyroid gland, then it is called Hashimoto’s auto-immune chronic lymphocytic thyroiditis…..a big name we simply refer to as Hashimoto’s Disease, and for this discussion we will simply say “chronic thyroiditis”.
Chronic thyroiditis takes on importance in several ways. First, years of inflammation can lead to destruction of normal thyroid tissue, which in time can result in low thyroid hormone levels in the blood, or a disorder known as “hypothyroidism”. This will require treatment with lifelong thyroid medication to insure that the patient always has normal levels of thyroid hormone in the blood stream.
Second, extended periods of inflammation can lead to scarring and fibrosis and sometimes the formation of a round, hard nodule that is very difficult to distinguish from a thyroid tumor or even a thyroid cancer. These patients will sometimes have to undergo a thyroidectomy for this reason.
Third, all scar tissue wants to get smaller. This is called the process of “contracture”. For example, if you get a 6-inch cut on your leg today, a scar will form. If you measure that scar next year, lets say, it may only be 5 ½ inches long. Well, scar tissue in the thyroid gland also wants to get smaller, but the thyroid gland sort of wraps around the windpipe and the esophagus to some degree. When this scar tissue undergoes contracture it can put pressure on those structures and produce what are called “compression symptoms”, that is, difficulty in breathing or swallowing. Some patients have actually choked on their food and have required the Heimlich maneuver because of the tightness that has been created. Others say that they have difficulty in breathing, especially when they lie down. These patients may require thyroidectomy for relief of these symptoms.
Fourth, about 30% of our patients with thyroid cancer are also found to have chronic thyroiditis. This does not mean that if you have chronic thyroiditis that you will be certain to get thyroid cancer, but note is made of this casual relationship. There are a few voices out there that would recommend that all patients with Hashimoto’s Disease undergo thyroidectomy. This seems a bit radical and a very large number of patients would undergo unnecessary thyroid surgery. Close and thoughtful observation by a thyroid specialist seems to be a prudent course of action for patients with chronic thyroiditis. Surgery can always be recommended if a patient develops a mass or symptoms which require further treatment, with little negative impact on prognosis. Please remember, I am discussing this topic in general terms for informational use only. There is no substitute for you and your physician making medical decisions based on your individual and specific case.
Fifth, some patients with chronic thyroiditis may suffer intermittent bouts of hyperthyroidism, as the disease is known to have flare-ups with release of excess quantities of thyroid hormone now and again. These flare-ups require medical treatment. Only rarely is surgery required because of failure of this medical treatment.
Sixth, there are rare instances of lymphoma developing within the thyroid gland. Lymphoma is a cancer of the lymphatic system and can manifest itself in many ways, one way being enlargement of lymphatic tissue or lymph nodes. In the thyroid gland, this is usually a rapidly growing mass and it is important to distinguish this from a possible anaplastic cancer of the thyroid, which is extremely lethal. Often these lymphoma patients have long-standing chronic lymphocytic thyroiditis, and the lymphoma is believed by some, to arise in this background of chronic inflammation and irregular cells.
The diagnosis of Hashimoto’s Disease is really quite straightforward. First, an experienced examiner can almost always suspect Hashimoto’s Disease based on physical examination alone. The gland is usually slightly enlarged, often tender to the touch, and the upper and lower parts of the thyroid lobes are usually somewhat blunted or thickened. Next, there is a blood test called the thyroid antiperoxidase antibody test that is used to detect the presence of the autoimmune antibodies. This is almost 100% accurate, but I have had a few patients I have treated for Hashimoto’s thyroiditis in spite of the fact that they had a negative antibody test. These people had classic symptoms and physical findings of the disease.
And this brings us to treatment. Surgery is not the treatment for Hashimoto’s thyroiditis alone, but it is used to treat some of the effects of the disease as described above. Probably the most appropriate treatment for chronic thyroiditis is the use of thyroid hormone medication. By taking the correct amount of thyroid hormone by mouth, the thyroid gland will soon stop functioning, as it will have no need to continue its work. The only reason the thyroid gland functions at all is because the pituitary gland in the brain sends down a hormone that stimulates the thyroid gland to work. By taking thyroid medication by mouth, we are actually “tricking” the pituitary gland into believing that the thyroid is functioning normally, and it therefore stops sending this messenger down to stimulate the thyroid gland to work. Once the thyroid stops working, it will sort of fall off the radar screen of the immune system and it will no longer send antibodies to attack the thyroid gland. If the gland is not attacked, there is no inflammation…no inflammation, no destruction of the normal thyroid tissue…therefore there will not be formation of scar tissue, and so on. This treatment then assures that the body will maintain normal thyroid hormone levels in the blood stream from the medication, and hopefully all of the bad effects of chronic thyroiditis can be avoided, such as hypothyroidism, tenderness, formation of thyroid masses, compression symptoms, and so on. It is important to note, however, that the earlier treatment begins, the more successful it is. Often I see patients after years of chronic inflammation and scarring and none of that can be undone or reversed by medical treatment.