The role of thyroid FNA cytology in pediatric malignant lesions: An overview of the literature

Abstract

When one is dealing with pediatric thyroid lesions, fine-needle aspiration is the first diagnostic tool for the correct characterization of these nodules. Despite the apparent infrequency of thyroid cancers in children, recent data from the National Cancer Institute prove that the incidence has been increasing, especially in adolescents. With the same data, a higher prevalence of well-differentiated cancers can be estimated, with 90% diagnosed as papillary thyroid cancer. Nonetheless, some publications have demonstrated that some specific malignant variants are more frequent in children and have a more aggressive behavior that justifies the increased number of surgical procedures. For this reason, the American Thyroid Association recommends the performance of neck ultrasonography and fine-needle aspiration cytology (FNAC) for the evaluation of pediatric thyroid nodules. Accordingly, as reported in adult thyroid series, several authors have documented the high sensitivity and diagnostic accuracy of FNAC in pediatric series; they have also shared the same problematic issues encountered in adult populations, mostly in the diagnosis of indeterminate lesions. To provide precise clinical and/or surgical management, the correct cytological identification of specific malignant histotypes/entities should be mandatory because lymph nodes, distant metastases, and extrathyroidal infiltration are more frequent within specific histotypes. A perusal of the literature shows that their identification has not been extensively studied and investigated in cytological samples. This review focuses on the analysis of data from the literature on the evaluation of malignancies and specific morphological features in pediatric thyroid lesions. Cancer Cytopathol 2017;125:594-603. © 2017 American Cancer Society.

Noninvasive follicular thyroid neoplasm with papillary‐like nuclear features in the pediatric age group

“…The diagnostic role of FNAC in the evaluation of pediatric thyroid lesions has been thoroughly assessed and reported in the literature . In fact, numerous articles have emphasized that the majority of thyroid lesions are easily recognized and correctly diagnosed on cytological specimens.…”

“…The study was independently evaluated and approved by the institutional review boards of both institutions. All details regarding the LBC method and ancillary techniques have been described in our previous articles …”

“…It is well known that well‐differentiated carcinoma of the thyroid and specifically papillary thyroid carcinoma (PTC) and its variants are among the most common endocrine malignancies in both adult and pediatric patients . Several publications have demonstrated that thyroid lesions in childhood have a 1.6‐fold higher cancer risk compared with those noted in adulthood .…”

Cytologic features of aggressive variants of follicular‐derived thyroid carcinoma

“…Since the 1st edition was published, several new variants of thyroid carcinoma have been described. The revised 2nd edition included a more detailed definition of the criteria for classifying some of the PTC variants and expanded the description of PTC variants to include solid, diffuse sclerosing, cribriform, and hobnail variants to improve their cytological identification . The 2nd edition also enriched the description of PDTC and ATC .…”

Malignant risk of indeterminate pediatric thyroid nodules—An institutional experience

“…Although thyroid nodules are less common in children than adults, an overview of the literature has showed that pediatric thyroid nodules are more likely to be malignant and carry a 1.6‐fold higher cancer risk than that of adult population . The Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer from The American Thyroid Association recommends fine‐needle aspiration (FNA) as an essential tool for the assessment and management of pediatric thyroid nodules, and utilizing The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) as a guideline to categorize FNA cytologic findings .…”