Aspirin Increases the Risk of Nondiagnostic Yield of Fine-Needle Aspiration and Biopsy of Thyroid Nodules.

Background: The link between the diagnostic yield of thyroid fine-needle aspiration and biopsy (FNAB) in patients taking antithrombotic or anticoagulant medications (AT/AC) remains poorly characterized.

Objectives: We studied the risk of obtaining a nondiagnostic sample with ultrasound-guided thyroid FNAB in patients taking AT/AC medications.

Methods: This is a retrospective cohort study using medical rec-ords of 556 patients who underwent thyroid FNAB.