Thyroid stem cells: danger or resource?

The thyroid gland has long since been known for its self-renewal ability, mainly in cases of hyperplastic disease such as goitre. Recently the amazing improvement in knowledge about stem cells has explained this potentiality. Some stem cell features and their clinical usefulness are summarized here, reviewing data from the literature: (1) the proven presence of adult stem cells in thyroid tissue, either normal, goitrous or neoplastic, bring with it important implications regarding tissue regeneration and oncogenesis; (2) modifying culture conditions and micro-environment stem cells have led to mature tissue with specialized functions. This has considerably changed the attitude of regenerative medicine and cancer research; (3) finally, identification of stem cells and stem cell markers in thyroid cancer, gives hope for the development of new therapeutic approaches in recurrent or treatment-resistant thyroid cancer.