Revisionist history uncovers a simplified molecular-based classification of differentiated thyroid cancer.

The diagnostic classification of differentiated thyroid cancer has been a longstanding topic of debate among pathologists, largely due to high interobserver variability. This complexity has increased with the expansion of tumor types and subtypes. However, molecular studies have revealed a simpler and less controversial approach, categorizing these lesions into RAS-like and BRAF p.V600E-like neoplasms. In this review, the authors propose a classification that is based on, but does not require, the confirmation of molecular alterations. This approach aligns with and helps inform the pattern-based assessment of tumor growth and cytologic atypia that is already widely used in clinical practice for preoperative patient stratification and tumor diagnosis, and promises a simpler conceptual understanding. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.