Chapter 11: Pediatric Differentiated Thyroid Cancers

Abstract

ABSTRACT The document discusses pediatric differentiated thyroid cancer (DTC), focusing on papillary thyroid carcinoma (PTC), which is increasingly prevalent globally, including in India. Despite a more aggressive initial presentation in children, the long-term prognosis is generally positive. Key differences between pediatric and adult DTC are highlighted, such as a higher risk of malignancy in children with thyroid nodules and common RET/PTC gene rearrangements. There is a debate on the age cutoff for defining pediatric DTC, but the document suggests that 18 years is considered appropriate in the Indian context. Diagnostic methods, including ultrasonography-guided fine needle aspirate (FNA) and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), are emphasized. The importance of genomic analysis for indeterminate cytology is also proposed. Treatment approaches involve total thyroidectomy due to higher multifocality in children, with consideration of potential complications. Post-operative risk stratification, utilizing the TNM staging system, is seen as crucial and correlates with disease-free survival. Post-operative staging includes TSH-stimulated thyroglobulin (Tg) and anti-thyroglobulin antibody (ATg) levels, along with a diagnostic whole-body 131I scan to assess surgical completeness. Radioactive iodine therapy (RAI) is recommended for iodine-avid persistent/metastatic disease, with an empirical activity of 30 mCi for remnant ablation and adjustments based on age or weight. Regular follow-ups include monitoring TSH-suppressed Tg, Anti-Tg levels, and neck ultrasound. Dynamic risk stratification at 2 years refines risk based on treatment responses. Genetic considerations reveal prevalent RET fusion oncogene and less common BRAF mutations, which are associated with RAI refractoriness. In summary, the document provides a comprehensive understanding of pediatric DTC, emphasizing the need for tailored guidelines in the Indian context. It covers various aspects of diagnosis, surgery, and post-operative care, with a focus on age-appropriate management and ongoing research in this specialized field.