Ultrasonographic characteristics of the follicular variant of papillary thyroid cancer in children and adolescents

Abstract

Objective To compare the sonographic features as well as clinical histopathological features of follicular variant papillary thyroid carcinoma (FVPTC) and conventional papillary thyroid carcinoma (CPTC) in pediatric patients. Methods From Jan. 2006 to Dec. 2017, 26 FVPTC patients and 82 CPTC patients were enrolled in this study. The clinical histopathological findings and the sonographic features were compared between the two groups. FVPTCs and CPTCs were divided into PTC-like and follicular neoplasm (FN) -like based on sonographic characteristics. Results The mean nodule size of FVPTCs was larger than that of conventional PTCs. Extrathyroid invasion and cervical lymph node metastasis did not have significant difference between CPTC and FVPTC patients (53.8% vs 62.2% and 76.9% vs 82.9%, respectively) . Multiple nodules (P=0.000) and distant pulmonary metastases (P=0.024) were more frequent in CPTCs than in FVPTCs (P<0.05) . The rate of an ill-defined margin (P=0.000) and calcification (P=0.003) in terms of sonographic features were lower in FVPTCs than conventional PTCs (P<0.05) . A Ⅴ+Ⅵ diagnosis of PTC on FNAC of FVPTCs was less common than that of conventional PTCs (P=0.014) . Multifocality (P=0.000) , extrathyroidal invasion (P=0.000) , and lymph node metastasis (P=0.000) were significantly different between PTC-like FVPTCs and FN-like FVPTCs. Conclusion FVPTC in children and adolescents shows a relatively larger size, more benign sonographic features, and a lower diagnostic rate of PTC by FNAC compared with conventional PTCs in pediatric patients. Key words: Children and adolescent; Thyroid papillary carcinoma; Sonography