Thyroid Year-in-Review 2025-2026: Precision Medicine and De-escalation in Contemporary Thyroidology.

The "Thyroid: Year in Review," presented at the AACE 2026 annual meeting, synthesized practice-influencing peer-reviewed clinical research published between March 1, 2025 and February 15, 2026. This narrative review, based on that presentation, highlights 2 overarching themes in clinical thyroidology: precision medicine and de-escalation when appropriate. In thyroid dysfunction, recent studies support lean body mass-based levothyroxine dosing and the metabolic integration of liothyronine. The management of thyroid nodules and differentiated thyroid cancer has shifted toward de-escalation, favoring nonsurgical interventions, active surveillance for low-risk malignancies, selective omission of radioactive iodine, de-escalation of surveillance strategies, and the complementary use of artificial intelligence with molecular testing to improve diagnostic accuracy in indeterminate nodules. This review summarizes these findings and their implications for contemporary evidence-based endocrine practice.