ESPE Abstracts

Background: South Korea is one of the adequate or excessive iodine nutritional state countries and high-iodine intake is related to papillary thyroid cancer. The prevalence of thyroid cancer of South Korea has increased and the proportion of thyroid papillary cancer has increased as 97.9–98.3% in 2010. Childhood thyroid cancer is rare, and the prevalence of thyroid cancer in pediatric population was reported as 20–26% of thyroid nodules worldwide. However, there have been few reports about thyroid nodule and cancer in pediatric population in Korea.

Objective and hypotheses: In the present study, we firstly investigated to know the prevalence and clinical findings of thyroid nodule and cancer in Korean pediatric populations.

Method: We investigated medical records of 311 patients had goiter, thyroid nodule, thyroid mass and thyroid cancer lower than 18 years of age. Twenty three patients were excluded of incomplete medical records and 186 were also excluded of diffuse goiter without nodule. Of the rest, fine needle aspiration biopsy (FNAB) was not done in 38 patients, therefore 64 patients were included in the present analysis.

Results: Female and male patients were 55 (86%) and 8 (14%), respectively, and mean age of the patients was 16.0±2.3 (8–18) years. Nodules on right thyroid lobe were in 37 (58%) patients, Left 23 (36%), both lobes 3 (5%), and was not described in one patient. Thyroidectomy was done to 15 patients and total thyroidectomy was done to 5 of the cancer patients. Of the 64 patients, 8 (12.5%) were finally diagnosed as thyroid cancer, and 6 (75%) were papillary cancer and 2 (25%) were follicular cancer. They were 1 male and 7 female patients and mean age was 15.6 years. No one was exposed to irradiation and 4 had positive thyroid autoantibodies. FNAB revealed malignant in 7 of them, and 1 s reported as benign on FNAB at first, however finally diagnosed as follicular cancer after 8 years of the initial visit. Otherwise, one patient was suspected to malignant on FNAB, the final pathologic diagnosis was nodular hyperplasia. Although the patient numbers were far different in the cancer patients and benign patients, we tried to compare clinical parameters in the two groups (cancer vs benign group). T3 levels were significantly higher in the cancer group than in the benign group (1.50±0.97 vs 1.06±0.19, P=0.004). Cancer group has more right lobe dominant than the benign group (78% vs 55%, P=0.009). Size or number of the nodules were comparable in the two groups. Cystic nature of the nodules was related to benign nodules. Although FNAB findings were discordant to the final diagnosis, 97% of FNA findings were concordant to the final diagnosis.

Conclusion: Thyroid cancer prevalence was slightly lower in Korean pediatric populations than that of worldwide report and it is dominant on right thyroid lobe. Papillary thyroid cancers are dominant in Korean pediatric populations but lesser prevalent than in Korean adults. As be known well, FNAB was highly diagnostic to predict the nodules to be malignant.