Thyroid Cancer
Thyroid cancer refers to
formation of malignant cells in the thyroid gland. Accumulation of these cells forms a cancerous growth in the
thyroid which often takes the form of a nodule (thyroid nodule) at the beginning.
There are various types of
thyroid cancer, named depending on group of cells affected:
- Papillarythyroid
cancer - papillary
thyroid cancer is the most common type of thyroid cancer; it affects mostly women aged between 30
and 40. Usually, papillary thyroid cancer grows slowly, and tends to have good prognosis when
diagnosed early. The tumor develops in the cells that produce the triiodothyronine, one of the
thyroid hormones.
- Follicular Thyroid
Cancer- this type of thyroid cancer, although a little slow growing, tends
to grow quicker than papillary carcinoma. It occurs mostly in women, principally women over 50 years old.
Prognosis of follicular cancers is not alarming when diagnosed and treated early. Usually, follicular thyroid cancers develop in the cells of the thyroid gland
that produce and secrete thyroxine (thyroid epithelial cells, also called follicular cells or principal cells).
- Medullary Thyroid Cancer - this form of thyroid cancer is more aggressive
than papillary and follicular cancers; it has poor prognosis. It tends to spread to distant organs in the
body: liver, bone, brain, and adrenal medulla. Medullary cancer usually begins in the parafollicular
cells (or C cells). This group of
thyroid cells produces and secretes calcitonin, an hormone that acts by keeping the blood
calcium at normal levels. About 25 percent of medullary thyroid cancer is due to genetic
disorders.
- Anaplastic thyroid cancer - unlike papillary carcinoma and follicular thyroid
cancer, anaplastic thyroid cancer is a very life-threatening condition; it tends to grow rapidly, and
resist to treatments. Due to its metastatic characteristic, anaplastic thyroid cancer has a very poor
prognosis. Usually, the tumor begins in the follicular cells of the thyroid, and affects most often people aged
60 and over. Anaplastic thyroid cancer is rare, representing about 3% of all thyroid cancers.
- Thyroid
lymphoma –
this is a very rare form of thyroid cancer. Usually, the cancer begins in the immune system cells of the thyroid (lymphoma
cells). Development of thyroid
lymphomais often associated with preexisting chronic autoimmune disease of the thyroid
gland called thyroiditis (inflammation of the thyroid gland).
Thyroid Cancer Statistics
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