Yield and costs of molecular diagnostics on thyroid cytology slides in the Netherlands, adapting the Bethesda classification.

Objective: To evaluate our institutional experience with molecular diagnostics (MD) on thyroid cytology smears, evaluate the costs and describe MD guided clinical management of indeterminate Bethesda III/V thyroid nodules.

Methods: We performed a retrospective review of 164 Bethesda III or V thyroid cytopathology reports subjected to MD from 2013 to 2020, that altered Bethesda classification or management. MD consisted of mutation and gene fusion analysis by next-generation sequencing (NGS) of morphologically analysed and selected cytological slides.