Diagnostic yield of fine-needle aspiration cytology for the detection of thyroid cancer in pediatric patients

Background: Despite the low frequency of thyroid nodules (TN) in children, one of every four is malignant. Fine-needle aspiration cytology (FNAC) has a high accuracy detecting thyroid cancer. Aim: To evaluate the performance of FNAC in TN in Chilean children to detect thyroid cancer. Patients and Methods: The pathological reports of 77 thyroidectomies and 103 FNAC carried out in patients aged less than 18 years, between 2002 and 2013 were reviewed. In 36 patients aged 15 +/- 2 years (77% women), both the reports of the thyroidectomy and FNAC were available. The cytological specimens were reclassified based on Bethesda 2010. The histology was classified as benign (nodular hyperplasia and follicular adenoma, n = 18), or malignant (papillary, follicular and medullar carcinoma, n = 18). The concordance of the cytology with the final biopsy report was calculated. Results: FNAC classified 13 specimens as definitively benign and 13 as definitively malignant. Among these, these concordances with the pathological study of the biopsy was 100%. Of six cytology tests considered "suspicious for follicular neoplasm" by FNAC, four were benign (67%), and two malignant (33%). Of four cytology tests considered "suggestive of carcinoma" by FNAC, one was benign (25%), and three malignant (75%). Conclusions: Among the studied children, there was a good concordance between FNAC and surgical biopsies. Therefore a FNAC should be carried out when malignancy is suspected in pediatric patients with a TN.