Towards harmonised paediatric thyroid cancer care: adult comparisons and gaps.

Differentiated thyroid carcinoma (DTC) in children and adolescents is a rare but increasingly recognised entity with distinct biological behaviour, clinical presentation, and outcomes compared to adult DTC. While paediatric cases often present with advanced disease, long-term survival is excellent in contrast to adult cases where prognosis declines with age and risk factors. Historically, paediatric management was extrapolated from adult data, but recent guidelines reflect a shift towards age-specific, risk-adapted care. A narrative review was conducted using PubMed (2000-2025), including clinical trials, cohort studies, reviews, and guidelines. We aimed to compare paediatric and adult DTC across epidemiology, clinical presentation, molecular characteristics, treatment strategies, outcomes, and existing guidelines, with the aim of identifying knowledge gaps for future harmonisation. We found that paediatric DTC is characterised by higher rates of multifocal and metastatic disease at diagnosis, distinct molecular drivers (e.g. RET/NTRK fusions), and higher radioiodine avidity. Surgical management is typically more extensive in children, while risk-adapted radioactive iodine therapy is increasingly practised in low-risk paediatric patients. TSH suppression is initially more aggressive, followed by gradual de-escalation. Despite higher recurrence rates in children, survival exceeds 95-98% even with distant metastases. While paediatric-specific guidelines have advanced (ATA 2015, ETA 2022), prospective paediatric data remain limited. We conclude that paediatric DTC is biologically distinct from its adult counterpart and requires tailored management. Coordinated, prospective research is needed to address current evidence gaps and support future harmonised European practice.