Malignancy rates and histopathological subtypes in pediatric thyroidectomy: a retrospective analysis from Acıbadem University (2010–2025)

Aims: Pediatric thyroid tumors are rare entities with distinct biological behavior and clinicopathological features compared with adult thyroid neoplasms. This study aimed to evaluate malignancy rates and histopathological subtypes in a large, single-center cohort of pediatric patients who underwent thyroidectomy, and to characterize the pathological spectrum of pediatric thyroid disease in a tertiary referral setting. Methods: This retrospective study included pediatric patients (≤18 years) who underwent partial or total thyroidectomy at Acıbadem Mehmet Ali Aydınlar University between January 2010 and October 2025. Clinical and pathological data were retrieved from institutional archives and electronic medical records. All histological slides were reviewed by two pathologists according to the World Health Organization classification of thyroid tumors. Tumors were categorized as benign or malignant, and malignant cases were subclassified by histopathological subtype. Pathological tumor–node–metastasis staging was performed according to the 8th edition of the American Joint Committee on Cancer TNM system. Descriptive statistics were used to summarize demographic and pathological findings.Results: A total of 174 pediatric thyroidectomy specimens were analyzed, of which 98 (56.3%) were malignant, 3 (1.7%) were low-risk neoplasms and 73 (42.0%) were benign. The cohort showed a marked female predominance, and most patients were adolescents at the time of surgery. Among malignant tumors, papillary thyroid carcinoma was the most frequent type, followed by less common differentiated and non-differentiated thyroid malignancies. Classical papillary thyroid carcinoma represented the predominant papillary subtype. Multifocal disease and regional lymph node metastasis were frequently observed at diagnosis, whereas distant metastasis was uncommon. Immunohistochemistry was applied selectively in a limited number of cases, with diagnosis primarily based on histopathological assessment. Pathological staging demonstrated a predominance of early T-stage primary tumors despite a high rate of nodal involvement.Conclusion: Pediatric thyroid tumors are rare entities with distinct biological behavior, frequently presenting with locoregional disease while maintaining an excellent prognosis. Papillary thyroid carcinoma remains the predominant malignant type, with histopathological evaluation serving as the diagnostic cornerstone and molecular characterization gaining increasing relevance. The establishment of national or multicenter registries integrating clinical, pathological, and molecular data is essential to advance evidence-based management in pediatric thyroid cancer.