|Causes of thyroid nodules can be classified as benign or malignant.|
Experts do not know the exact cause of thyroid nodules. But they do know that people who have been exposed to radiation have a greater chance of developing thyroid nodules. Exposure to environmental radiation or past radiation treatment to the head, neck, and chest (especially during childhood) raises your risk for thyroid nodules.
Experts know that thyroid nodules run in families. This means you are more likely to have a thyroid nodule if one of your parents has had a thyroid nodule. Also, if you have another thyroid condition (such as goiter), you may have a greater chance of developing thyroid nodules.
Benign Thyroid Nodules
- Multinodular goiter: Multinodular goiter is an overall enlargement of the thyroid gland (called goiter) can result from nodules containing too many normal thyroid cells (referred to as hyperplasia) and/or filled with extra colloid. Colloid is the protein-containing substance normally storing thyroid hormone inside the thyroid gland.
- Hashimoto's thyroiditis: Hashimoto's thyroiditis is the most common form of underactive thyroid disease, this form of hypothyroidism can be associated with thyroid nodules and goiter.
- Thyroid Cyst: Commonly caused by a nodule which is bleeding or degenerating (breaking down), these blood or colloid-filled nodules can be associated with thyroid pain.
Benign thyroid tumors (thyroid adenomas)
- Hurthle cell adenoma
- Follicular adenoma
Malignant Thyroid Nodules
Thyroid Cancer (also called thyroid carcinomas)
- Papillary thyroid carcinoma
- Follicular thyroid carcinoma
- Anaplastic thyroid carcinoma
- Medullary thyroid carcinoma
- Thyroid lymphoma
- Metastatic cancers from other sources, including breast, kidney and lung cancers