Context: The immune system seems to play a key role in preventing metastasis and recurrence of thyroid cancer. T regulatory lymphocytes (Tregs) and natural killer (NK) cells play an important role in the dysfunction of the host immune system in cancer patients.
Objective: We investigated thyroid gland infiltration by Tregs and NK cells in patients with papillary thyroid cancer (PTC) and thyroid nodular goiter (TNG).