The ATA 2025 histotype-based risk stratification of differentiated thyroid cancer: the revenge of morphologic pathology?

Abstract Differentiated thyroid cancer (DTC), encompassing papillary and follicular carcinomas, is the most common endocrine malignancy worldwide. Although incidence has increased, largely due to expanded imaging and diagnostic scrutiny, disease-specific mortality remains low, emphasizing the need for precise risk stratification to balance oncologic safety with avoidance of overtreatment. For two decades, postoperative management has progressively shifted from anatomy-based staging toward dynamic risk assessment incorporating molecular data. Building upon the 2015 and subsequent updates of the American Thyroid Association (ATA) guidelines and aligned with the 2022 WHO classification, the emerging 2025 ATA framework consolidates a histotype-centered paradigm. In this paper, we critically examine this transition and contextualize the recalibration of molecular testing within contemporary evidence. We detail how distinct histotypes – papillary (including aggressive variants), follicular, and invasive encapsulated follicular variants, oncocytic carcinoma, poorly differentiated, and high-grade follicular cell–derived carcinomas – exhibit divergent biological behaviors that are best captured by high-quality histopathology. We further discuss the DATA framework (Disease status, ATA risk, Tumor biology, patient-specific factors) as an integrated, dynamic model guiding therapeutic intensity over time. While routine molecular profiling offers limited incremental prognostic value in low- and intermediate-risk DTC, it remains indispensable in progressive, metastatic, and radioiodine-refractory disease for selection of targeted therapies. Thus, contemporary guidelines and our analysis support a biologically coherent hierarchy in which morphology anchors early-stage management and genomics refines advanced care.