Early Familial Non-Medullary Thyroid Cancer: Differences with Late-Onset and Sporadic Forms

These findings underscore the relevance of age at disease onset in shaping the clinical phenotypes of FNMTC. The distinct pathological features of early-onset vs late-onset FNMTC suggest different pathophysiological mechanisms, with the former likely driven by direct genetic/oncogenic alterations, and the latter influenced by autoimmune thyroiditis-related carcinogenesis, a hypothesis that warrants further investigation in larger prospective studies.