Thyroid nodules may also rarely produce the thyroid hormone, thyroxine, in excess. This is uncommon but the reason why all patients with thyroid nodules should have a blood test for thyroid stimulating hormone (TSH). Thyroid nodules that produce extra thyroid hormone can cause symptoms of hyperthyroidism which include:
- Unexplained weight loss
- Heat intolerance
- Rapid or irregular heart rate
Thyroid Nodules: Potential Causes
Several conditions may cause or predispose to the development of thyroid nodules including:
Overgrowth of normal thyroid tissue
The reason why these thyroid nodules occur is not well understood. These thyroid nodules are commonly called follicular adenomas or thyroid adenomas. (the follicular cell is a normal appearing thyroid cell). Follicular adenomas are clearly not cancerous and are not worrisome and do not require removal except if they are symptomatic due to their size. The rare follicular adenoma or thyroid adenoma will overproduce thyroid hormone and be the cause of hyperthyroidism. For some reason these excessive thyroid hormone producing adenomas lose their ability to be regulated by the pituitary glands production of Thyroid Stimulating Hormone (TSH).
Thyroid cysts are fluid filled cavities caused by degenerating thyroid adenomas, congenital cysts, or overproduction of a fluid produced by the thyroid called colloid.
Inflammatory diseases of the thyroid (called thyroiditis)
Hashimotoâ€™s thyroiditis or Hashimotoâ€™s disease is a chronic inflammatory condition of the thyroid gland caused by an autoimmune event where the patient develops antibodies to thyroglobulin (a normal protein produced by the thyroid gland). Long standing Hashimotoâ€™s thyroiditis is frequently associated with diseased thyroid hormone production call hypothyroidism. Hashimotoâ€™s thyroiditis may also be associated with thyroid pseudo-nodule formation. These pseudo nodules are not concerning thyroid nodules. Pseudo nodules found on ultrasound in thyroiditis patients will come and go based upon unknown issues.
Multinodular disease of the thyroid (also called Multinodular Goiter or just â€œGoiterâ€)
Multinodular goiter is a thyroid gland which contains multiple thyroid nodules. The cause of multinodular goiter is not known but in some instances there may be a strong family history of goiters. Multinodular goiters can be quite massive and extend throughout the neck and well into the chest cavity.