There are four types of thyroid cancer: papillary, follicular, medullary, and anaplastic. The types of thyroid cancer are classified by which cells they originate from and their appearance. Each type is unique with varying treatment methods, prognoses, and survival rates.
Diagnosis of thyroid cancer is made by a biopsy, using a fine needle aspiration method in most cases. Once a sample of the thyroid tissue is collected through a biopsy, it is then examined under a microscope by a pathologist (a physician who specializes in diagnosing diseases by examining blood, tissue, and fluid samples).
Papillary Thyroid CancerThis is the most common type of thyroid cancer, accounting for approximately 80-90% of all cases. Papillary thyroid cancer is very treatable, and in many cases, curable. While papillary thyroid cancer often spreads to the cervical lymph nodes, it does not commonly spread to distant organs, like in other types of cancer. If it does metastasize, the bones and the lungs are likely sites of metastasis.
Papillary thyroid cancer is strongly associated with radiation exposure. It is most often seen in adults aged 30-50.
Follicular Thyroid CancerFollicular thyroid cancer is the second most commonly diagnosed type of thyroid cancer, accounting for approximately 15% of diagnoses. It is usually detected by the presence of a small, painless lump in the neck. The disease occurs more often in women than in men. Most people diagnosed with this type of thyroid cancer are under the age of 40.
Metastasis occurs more often in follicular thyroid cancer than in papillary cancer, largely due to vascular invasion, allowing the disease to spread through the bloodstream. The bones and lungs are possible sites for metastasis, as in papillary thyroid cancer. Age greatly affects the prognosis of a person with follicular thyroid cancer; younger patients tend to fare better than older patients.
Unlike papillary carcinoma, follicular cancer is not as strongly related to radiation exposure.