Risk of thyroid cancer in pediatric patients with Hashimoto's thyroiditis

Abstract

Introduction: Hashimoto’s thyroiditis (HT) is highly prevalent and has attracted growing interest because of its potential association with thyroid cancer, suggesting that chronic inflammation may contribute to the development of thyroid neoplasms. In addition, the incidence of thyroid cancer in children has increased over recent decades.

Objective: To summarize the available evidence regarding the association between Hashimoto’s thyroiditis and thyroid cancer in children and adolescents.

Case Presentation: A 14-year-old female patient with a history of Hashimoto’s thyroiditis receiving levothyroxine treatment. During follow-up, thyroid ultrasound identified a 14-mm solid hypoechoic nodule with microcalcifications located in the thyroid isthmus. Fine-needle aspiration biopsy reported a follicular lesion of undetermined significance (Bethesda III). The case was evaluated by a multidisciplinary team to determine the most appropriate diagnostic and therapeutic approach.

Discussion: This narrative review found a higher prevalence of HT among pediatric patients with papillary thyroid carcinoma (PTC), suggesting an association, although not a causal relationship. The presence of HT has not been consistently associated with poor prognostic features such as extrathyroidal extension, capsular invasion, or lymph node metastases. Most studies included patients who underwent thyroidectomy, which limits the generalizability of the findings.

Conclusion: There is an association between autoimmune thyroiditis and an increased risk of differentiated thyroid cancer in children and adolescents. Careful follow-up of pediatric patients with HT and thyroid nodules is recommended, including ultrasound evaluation and fine-needle aspiration biopsy when indicated.