How to do it: ultrasound-guided fine-needle aspiration of thyroid nodules that commonly result in inappropriate cytology

Ultrasound (US)-guided fine-needle aspiration (US-FNA) is widely used for the diagnosis of thyroid nodules and other neck masses, and it is now considered the most simple, safe, accurate, and minimally invasive procedure for this purpose. The aim of this article was to present US-FNA for thyroid nodules with difficult or unusual sampling conditions. A better understanding of a wide range of US-FNA techniques will be helpful to the practicing and experienced doctors for diagnosing thyroid nodules or neck masses that are difficult to sample accurately.