Cytology-Radiology Correlation Series: Thyroid cytopathology

Thyroid ultrasound is typically the first step in the workup of thyroid nodules. Ultrasonographic features of thyroid nodules can be used to evaluate their risk of malignancy using risk stratification systems to determine whether a nodule is suspicious enough to warrant a more invasive fine-needle aspiration (FNA) for further evaluation. For this review, the authors described and compared two major risk stratification systems, the American Thyroid Association classification system and the American College of Radiology Thyroid Imaging Reporting and Data System, and explored corresponding ultrasound and cytology findings in the thyroid for commonly encountered entities in cytopathology practice.