Sensitivity of fine-needle biopsy in detecting pediatric differentiated thyroid carcinoma

Differentiated thyroid carcinomas (DTC) are uncommon in children. Since the frequency of malignancy is assumed to be high in pediatric symptomatic thyroid nodules, carcinomas should be ruled out reliably. The objective of this study was to assess the sensitivity of fine-needle biopsy (FNB) in diagnosing children with DTC.

We retrospectively analyzed 15 years of data from the GPOH-MET registry, a database by the German Society for Pediatric Oncology and Hematology (GPOH) with a focus on malignant endocrine tumors (MET). We reviewed data on pediatric patients with DTC who had undergone FNB. FNB results were classified according to well-established guidelines.

During the study period, 206 children with a histological diagnosis of DTC were entered into the GPOH-MET database. Fifty of those patients aged 3.6-17.3 years (mean, 12.3 years) had undergone FNB preoperatively. Forty-one were diagnosed with papillary thyroid carcinoma (PTC), seven with follicular thyroid carcinoma (FTC), and two had DTC not otherwise specified. Of the first FNB performed on each patient, the cytological specimens were diagnosed as benign in 13 cases, malignant in 14, suspicious in 9, follicular neoplasms in 6, and unsatisfactory in 8. The sensitivity of FNB in detecting DTC was 69.0%.

Our results reflect the current practice of pediatric thyroid FNB in Germany. In order to improve its usefulness, FNB should always be performed by experienced physicians. Furthermore, a central review of all specimens is necessary to ascertain the validity of the cytological diagnosis and to introduce immunocytological and molecular methods.