The thyroid gland is a small butterfly shaped thing sitting just under the skin and muscles in front of the neck, under the voice box. Usually , it is not visible. When it becomes big, due to some disease or abnormality, it is commonly called‘Goitre’. Then it is prominent as a swelling in front of the neck, more visible when a person swallows.
Thyroid secretes a hormone called Thyroxine. It is a molecule that contains Iodine. People need to eat adequate Iodine, to prevent a common type of swelling of the thyroid gland. That is the main reason for adding Iodine to the salt that we use.
Absence or inadequate quantity of the hormone, usually due to a disease of the gland is called hypothyroidism. People with this disease may put on weight, and are usually intolerant to cold. There may be skin and hair changes, and some other symptoms and signs. The thyroid gland may or may not be enlarged in this condition. This disease is diagnosed by a blood test, and the treatment is by eating tablets containing the hormone. The treatment is usually easy and does not require surgery.
Overproduction of Thyroxine causes hyperthyroidism. This disease causes affected people to become thin and wasted, despite eating well. There may be hair loss, irritability, heart problems and many other effects. The thyroid gland is usually enlarged in this condition. The treatment may involve medicines, a thing called radio iodine therapy, and surgery.
The thyroid gland may show overall enlargement or a part of the gland may be enlarged, like a small grape. This is called a thyroid nodule. The entire gland may be enlarged, and studded with nodules, making it lumpy. This is a multi nodular goitre. The nodules may be very small, and may be seen only on scans, like an ultrasound scan.
Nodules that can be felt, are common. Five to eight percent of women have them. If you do ultrasound scans, a much larger percentage of people may show smaller nodules that are not felt. Only some nodules are dangerous. Only some nodules or enlargements of the glands need to be treated by surgery. Enlarged glands can press on the wind pipe and the food pipe, causing difficulty in breathing and swallowing. Then surgery is required, even when there is no hyperthyroidism or risk of cancer.
To decide about treatment, enlargement and nodules of the thyroid gland hinges on three things:
Blood tests for thyroxine and TSH levels. TSH is a hormone secreted from pituitary in the brain and its levels are inversely related to Thyroxine levels. When thyroxine drops, TSH increases and vice versa. This test shows whether hypo or hyperthyroidism is present. Depending on that, treatment and further tests have to be decided.
The second test is an ultrasound scan. It shows the nodule, and may indicate whether a nodule is likely to be a cancer. The scan also makes it easier to do a needle biopsy, which is many a time, combined with the scan.
The needle cytology is the third major test. It is called and FNAC. A needle is put into the nodule and sucked, and it is then sprayed into a glass slide and looked under a microscope by the pathologist. By looking at the cells, the chances of a nodule being a cancer can be assessed.
Other tests may be needed. One of them is the radio-iodine scan or a technetium scan. The treatment of thyroid cancers may involve radio-iodine therapy, done by nuclear medicine specialists.
Depending on the results of the tests, surgery may be required. Hemi thyroidectomy is removal of only half of the gland. Total thyroidectomy os the removal of the whole gland.
Thus we can see that for diagnosis and treatment of thyroid gland diseases, many specialists have to be involved. They are the thyroid surgeon, endocrinologist, ultrasonologist, pathologist and the nuclear medicine specialists. Occasionally, other specialists are also needed. It is best to get treated in a place where all these facilities are available. This is because, many aspects of the tests, like the result of the scan and the needle cytology, depend critically o the experience of the performing expert.
Studies have shown that complications after thyroid surgery are much less, when it is done by surgeons who do it regularly and are specialists in its care.
The common complications are due to injury to the nerves supplying the voice box, the vocal cords, which may affect breathing and voice. The parathyroid glands may be injured, which may cause the blood calcium levels to drop dangerously. When the surgery is done by an experienced surgeon, permanent voice problems and blood calcium problems are extremely rare, less than one percent. Temporary voice changes and calcium drop are commoner, but return to normal.
Patients can be admitted on the day of the surgery or the evening before, and can be discharged on the third day after surgery. There will be a small scar on the neck, which may not be noticeable after sometime. Endoscopic approaches are there, that can avoid the scar in the neck. These are usually more extensive procedures and are costlier.