Papillary and follicular cancer , or carcinoma, account for about 80-85% of all thyroid malignancies.
Thyroid Cancer
Papillary and Follicular Cancer, or CarcinomaPapillary and follicular cancer , or carcinoma, account for about 80-85% of all thyroid malignancies. They get their names from their appearance under the microscope. Some are pure papillary, some are purely follicular in nature, and some are mixed, that is, both types of cancer cells may be present in the same tumor. In fact, some of these tumors are actually referred to as “follicular variant of papillary carcinoma”. The important thing to understand is that 1) the typical forms of these cancers are quite curable in a very large percentage of cases and, 2) they behave in somewhat dissimilar ways, and affect slightly different age groups, though there are often exceptions to the rule.
Papillary carcinoma is more common in the younger age groups, though oldsters can also get the disease. Any thyroid mass in a child or teenager should be considered highly suspicious for papillary carcinoma until proven otherwise. Papillary cancer can be a solitary nodule, but it can be found to be multicentric within the gland in at least 20% of cases. If it’s going to spread, it prefers to do so through the lymphatic system, that is, spreading to lymph nodes. The first lymph nodes in danger are those that live next to the trachea or windpipe. These are called the “paratracheal lymph nodes”and we have seen an incidence of metastasis here of about 50% in our cases of papillary cancer going back to 1949. For this reason we recommend removal of these nodes when total thyroidectomy is done for known papillary cancer. The next group of nodes that this cancer may spread to are in the neck, and they may be the lymph nodes just above the collar bone or the nodes that live along the mid-portion of the jugular vein. Excluding the paratracheal nodes, if a patient has spread of her thyroid cancer to the other lymph nodes of the neck, a complete removal of all the lymph nodes of the neck on that side should be performed. The boundaries of such an operation are the collar bone to the trapezius muscle to the horizontal line of the jawbone to the midline. Any compromise here can and does end up necessitating multiple procedures in many cases. Indeed, one of the more common problems I see is inadequate initial surgery resulting in multiple procedures. As I write this I am waiting to see a lady from California who has already had three procedures. Removal of all the lymph nodes from one side of the neck is called a “modified radical neck dissection” and when performed correctly it should obviate the need for any more surgical treatment with regard to the lymph nodes on that side of the neck. Not enough surgeons are trained in the Art and Science of this procedure.
Papillary cancer can spread to other parts of the body as well, but this is usually a late manifestation of the disease. For this reason, radioactive Iodine is sometimes given following surgery to kill any cancer cells that may have escaped to other places before the surgical removal of the tumor.
Follicular cancer affects women a little more than men and is usually, but not always, in a little older age group. Follicular cancer prefers to spread through the blood stream more than through the lymph node system. Usually the tumor is solitary, but total thyroidectomy is always performed because we have to remove all of the functioning thyroid tissue in the neck that we can so that the dose of radioactive Iodine given later can and will actually get to any cancer cells that might have spread. If we left the “normal” half after taking out the half with the follicular cancer in it, then any Iodine we would give the patient would all go to that normal thyroid tissue left behind in the neck and not get to the cancer cells that might be lingering elsewhere in the body.
Finally, some tumors are partly papillary and partly follicular, and their treatment plan has to be individualized for that patient.
