TG and Hashimoto thyroiditis: For low-risk DTC patients treated with lobectomy, an increase in Tg values over time suggested a growing thyroid tissue or tumor, and an increase in TgAb values suggested coexistent Hashimoto thyroiditis in residual thyroid tissues (especially in patients diagnosed with Hashimoto thyroiditis by surgical histopathology) or tumor relapse (5, 23–25).