There are essentially four types of thyroid cancer.
1. Papillary Thyroid Cancer: This type of cancer is generally observed between the ages of 20-50 and is three times more common in women than in men. It is also the most common type of thyroid cancer observed in children under the age of 14. In fact, 80% of all thyroid cancers are of this type. These tumors can be less than 1 cm in diameter and may not show any growth or symptoms for many years (sometimes as long as 30 years). They are generally detected coincidentally, for instance, during the surgical removal of the gland for goiter or hyperthyroidism. In recent years, they have been frequently detected through sensitive ultrasonographic examinations and other imaging tests during check-up programs. A study we conducted showed that this type of cancer is present in 2% of the population in Turkey and that they are totally unaware that they carry the disease. This figure can be as high as 30% in some countries such as Japan and Finland. This is largely due to the high consumption of seafood and excessive intake of iodine which leads to inflammation of the thyroid gland and eventually cancer.
Complete removal of the thyroid gland due to papillary thyroid cancer. A grey-colored tumor without capsule can be seen in the left lobe.
The treatment for papillary thyroid cancer is surgery, namely total thyroidectomy. Following surgery, if a “microcancer” measuring less than 10mm is present, it is a generally accepted practice to refrain from giving the patient any other treatment other than thyroid hormone replacement to suppress the TSH level. However, radioactive iodine treatment must be given to the patient six weeks after surgery if the cancer has spread to the lymph nodes, the cancer has extended beyond the thyroid capsule or the cancer is larger than 10mm. This treatment reduces the risk of the disease returning in the form of distant metastases or local recurrence in the neck. If the patient has lymph node involvement in the neck, the lymph nodes must also be removed together with the thyroid gland. If this is suspected before thyroid surgery, the lymph node alone must not be surgically removed in any way whatsoever prior to thyroid surgery. If necessary, a fine needle biopsy can be performed for diagnosis, but the lymph node must only be removed together with the thyroid gland. This type of surgery is called Total Thyroidectomy and Modified Radical Neck Dissection Surgery.
Patients are followed by measuring their TSH and thyroglobulin levels. While a TSH test indirectly shows us the amount of thyroid hormone in the blood, a thyroglobulin value of around “ 0” indicates that the disease has been cured. However, in some cases, the disease can recur despite a low thyroglobulin level.
These patients are considered the most “fortunate” among all cancer patients as 90% of them are able to lead a normal healthy life following successful treatment.
2. Follicular Thyroid Cancer: This type of cancer is seen more in women aged between 40-60 and accounts for 10% of all thyroid cancers. Follicular thyroid cancer is the most difficult to diagnose as neither a fine needle biopsy prior to surgery nor a frozen section during surgery is effective in determining whether or not the lesion is cancerous. A definitive diagnosis can only be made if there is an invasion of the capsule surrounding the cell mass, which makes surgery the only option. While the invasion of the capsule or the blood vessels is indicative of follicular thyroid cancer, no invasion indicates a benign follicular adenoma.
Complete removal of the thyroid gland due to follicular thyroid cancer. A tumor with capsule can be seen in the left lobe.
As in the papillary type, treatment for follicular thyroid cancer is surgery followed by radioactive iodine treatment - no matter how big or small the cancerous tumor is. Eighty percent of patients lead a normal healthy life following successful treatment.
3. Medullary Thyroid Cancer: This type of cancer is observed between the ages of 1- 20 in genetically transmitted familial types and after the age of 40 in non-familial (sporadic) types. It accounts for 5% of all thyroid cancers and generally emerges with a lump in the lateral neck, which is usually a metastasis to the lymph nodes. Treatment for medullary thyroid cancer is a total thyroidectomy and lymph node dissection in the central neck area and on the side of the tumor. Radioactive iodine treatment is not given after surgery as the cells - called ‘parafollicular cells' - from which the tumor develops is different from main follicular cells which can absorb iodine. In the follow-up of these patients, the measurement of calcitonin levels is important. Sixty percent of patients lead a healthy life following successful treatment.
Specimen after total thyroidectomy due to medullary thyroid cancer in the left lobe and lymph node dissection material
4. Anaplastic Thyroid cancer: This type of cancer is the most ruthless of all. It accounts for 5% of all cancers. It usually emerges after the age of 60 as the result of a sudden change in the biological behavior of a papillary or follicular cancer which has remained untreated for many years. It grows very rapidly and is so aggressive that surgery is usually not an option. External beam therapy can be given to the patient to reduce discomfort.
A rapidly growing anaplastic-type cancer which has spread to tissues under the skin. Surgery is generally not an option with this type of cancer.
After total thyroidectomy and central & lateral lymph node dissection due to metastatic thyroid cancer
Closure and post-operative drainage of the skin .
Two sided total thyroidectomy neck lymph node dissection