Medullary thyroid cancer is a rare form of thyroid cancer that begins in the parafollicular cells and is diagnosed through ultrasound-guided fine-needle aspiration. Symptoms include excessive calcitonin, diarrhea, flushing of the skin, and lumps in the neck. Treatment involves thyroidectomy, chemotherapy, and external radiation. Prognoses depend on the stage of the cancer when discovered and treated.
About 35,000 Americans are diagnosed with thyroid cancer each year, and on average, medullary thyroid cancer is about 3 percent of these. Unlike most thyroid cancers, medullary thyroid cancers begin in the parafollicular cells and a primary indicator is an overproduction of a hormone called calcitonin. Diagnoses are usually made using ultrasound-guided fine-needle aspiration, and nearby lymph nodes are also biopsied for metastases. There are four forms of medullary thyroid cancer; most of these forms require thyroidectomies, chemotherapy, and external radiation, because medulla has a worse prognosis than other thyroid cancers and is more likely to recur. Symptoms may not occur initially; in the case of multiple endocrine neoplasia (MEN) syndromes, symptoms often do not appear, however patients are diagnosed due to incidence in a family member, as this form is a genetically transmitted susceptibility.
When symptoms do occur, they are typically due to excessive calcitonin and calcitonin gene products, presenting as diarrhea and flushing of the skin, often indicating liver metastases. Physical examination may reveal a lump or lump at the base of the neck. There may also be breathing problems, jaundice and abdominal pain and swallowing problems or voice changes due to growth of nodules in nearby structures. Bone tenderness can also indicate metastases to the bone; other organs that are metastatic candidates are the lungs, brain, lymph nodes, and adrenal glands. Immediate thyroidectomy is the recommended initial treatment for these symptoms in all forms of medullary thyroid cancer except the MEN syndromes.
MEN syndromes are highly familial and constitute approximately 25% of incidences of medullary thyroid cancer, as the determinant of the mutated gene MEN-II-A, which is genetically distinct from MEN-II-B and may have accompanying hyperparathyroidism and pheocomocytoma the cancer. If a pheocomocytoma is present, it should be treated before a thyroidectomy. MEN-II-B will only have pheocomocytoma endocrine disease and medullary thyroid cancer. Another form of medullary cancer is known as sporadic medullary thyroid cancer; about 60 percent of medullary tumors are of this type and in almost all cases they do not metastasize at all. The remaining form of medullary thyroid cancer is also a type of hereditary carcinoma due to genetic mutation, but it is the least aggressive of all medullary forms, although it sometimes metastasizes through the blood and lymphatic systems to other organs.
After thyroidectomy, which involves the removal of the thyroid gland and nearby lymph nodes, follow-up care mostly consists of some chemotherapy and regular testing for recurrence. The use of radioactive iodine is not indicated because, unlike other thyroid cancers, medullary thyroid cancer cells are not of a cell type capable of absorbing or reacting to radioactive iodine. External beam radiation is usually used to prevent recurrence and to provide palliative care for those who are unfit for surgery. Yearly chest X-rays and biennial blood tests to check for excessive calcitonin are usually indicated.
Prognoses are related to the stage of the cancer when discovered and treated. For stage one, the five-year survival rate is 100%, for stage two it’s 98 percent, for stage three it drops to 81 percent, and in stage four, the five-year survival rate is 28 percent . The overall rate for 10-year survival is 65 percent. Prognostic factors that could influence these numbers are older age, prior neck surgery, and MEN-II-B malignancy syndrome, all of which correlate with worse outcomes. From international morbidity statistics, medullary thyroid cancer rates are very similar to those in the United States.
Protect your devices with Threat Protection by NordVPN
