Endocrine Abstracts

Introduction Thyroid cancer (TC) is rare in childhood. The aim of the present study was to describe the tumoral characteristics of children and adolescents with TC and to investigate the frequency of microcarcinomas in that population.

Methods We studied the medical records of 101 children and adolescents (≤ 21 years-old) who were diagnosed with TC between January 1977 and December 2011 in Theagenio Cancer Hospital. The following characteristics were recorded for each patient: year of diagnosis, patient’s age and gender, histological type, tumor size, number of tumor foci, presence of: lymph node metastases, thyroid capsule invasion, vascular invasion and infiltration of the thyroid parenchyma or surrounding soft tissues. Microcarcinomas were defined as unifocal intrathyroidal papillary cancers ≤10 mm in diameter without lymph node involvement.

Results Tumor size was larger in patients with follicular, medullary and poorly differentiated thyroid cancer (33.5±10.7, 35.7±22.3 and 32.7±21.9 mm, respectively; P<0.05). Vascular invasion was more frequent in patients with follicular and poorly differentiated thyroid cancer (66.7% in both types; P<0.005). Patients older than 18 years showed infiltration of the thyroid parenchyma and the surrounding soft tissues less frequently than younger patients (42.4 vs. 64.3%, P<0.05 and 15.3 vs. 35.7% respectively, P<0.05). Other characteristics did not differ between patients older and younger than 18 years. There was no difference in any of the characteristics at diagnosis between males and females, or between the age groups ≤ 14, 15–18 and > 18 years-old. Among the 89 patients with papillary TC and their variants, tumors ≤ 10 mm were present in 30 (33.7%) and microcarcinomas were present in 12 patients (13.5%).

Conclusions TC in children has more invasive characteristics than adolescents. 20.2% of patients had small (≤ 10 mm) but invasive tumors. True microcarcinomas (13.5%) represent a minority of thyroid tumors.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector