Histology-based and cytology-based needle sampling for targeted next-generation sequencing in the indeterminate thyroid tumors

Abstract

Purpose: To establish the optimal and minimally invasive diagnostic approach for targeted next-generation sequencing (NGS) in the indeterminate thyroid tumors.

Methods: The patients with indeterminate thyroid tumors were prospectively recruited and analyzed in a single tertiary medical center. We performed FNA and core needle biopsy (CNB) at the surgical specimens to confirm the quality of each sampling procedure. Cytological diagnosis by FNA, histological diagnosis by CNB and confirmed diagnosis by final surgery were compared to demonstrate the agreement among these approaches for the indeterminate thyroid tumors. The quality of the samples from FNA and CNB was evaluated, respectively to determine the optimal approach for targeted NGS. Finally, we performed ultrasound-guided CNB and FNA (US-CNB and US-FNA) on one case to confirm the clinical feasibility of being a pre-operative minimally invasive diagnostic approach.

Results: A total of 6 female patients (average age: 50.83 ± 15.18 years) with indeterminate thyroid tumors (average size: 1.79 ± 0.91 cm) were recruited for further analyses. The pathological diagnoses could be obtained by CNB in the first five cases, and the sample quality of CNB for targeted NGS was better than that of FNA, even after 10X dilution. The gene mutations associated with thyroid malignancy could be detected by NGS. In the case treated with US-CNB, the pathological and targeted NGS results were successfully obtained, which suggested the possibility of thyroid malignancy to facilitate immediate decision of subsequent treatment.

Conclusion: CNB could serve as a minimally invasive diagnostic approach in the indeterminate thyroid tumors by providing pathological diagnoses and qualified samples for detection of mutated genes, which facilitates appropriate and immediate management.

Keywords: Core needle biopsy; Fine needle aspiration; Indeterminate thyroid tumors; Minimally invasive diagnostic approaches; Next-generation sequencing.