US-guided Fine-Needle Aspiration of Thyroid Nodules: Indications, Techniques, Results

Abstract

Fine-needle aspiration (FNA) biopsy of thyroid nodules is minimally invasive and safe and is usually performed on an outpatient basis. However, the optimal application of FNA requires not only technical skill but also an awareness of the limitations of the procedure, the indications for its use, the factors that affect the adequacy of the biopsy specimen, and the postprocedural management strategy. Ultrasonographic (US) features that are considered indications for FNA include single and multiple thyroid nodules. The results of FNA biopsy are operator dependent. In addition, the results may be affected by the lesion characteristics, the accuracy of lesion and needle localization, the method of guidance, the number of aspirated samples, the needle gauge, the aspiration technique, and the presence or absence of on-site facilities for immediate cytologic examination. With regard to postprocedural management, nodules that are diagnosed as benign on the basis of an adequate FNA specimen should be monitored with follow-up US. Circumstances that necessitate repeat FNA include sample inadequacy, nodule enlargement, cyst recurrence, or clinical or imaging findings that arouse suspicion about the presence of a malignancy even when cytologic findings in the biopsy specimen indicate benignity. Supplemental material available at radiographics.rsnajnls.org/cgi/content/full/28/7/1869/DC1.

Contributory Factors to Hemorrhage After Ultrasound-Guided Fine Needle Aspiration of Thyroid Nodules with an Emphasis on Patients Taking Antithrombotic or Anticoagulant Medications

“…US-FNA of thyroid nodules is a simple, minimally invasive, and safe procedure, usually performed in the outpatient clinic (2). The most common complications are local pain or discomfort and minor hematomas (4,6).…”

“…If the patient is taking an anticoagulant or antithrombotic, stopping the medication for 3 -10 days is recommended before and after US-FNA (4,5,9,11,17,18). However, performing US-FNA in patients taking anticoagulant or antithrombotic remains controversial and lacking in evidence, such as randomized controlled study (2,4,7,9,16,33). A recent study of 593 patients who underwent US-FNA on a total of 788 neck lesions reported no significant differ- ences in hematoma formation between patients who were on antithrombotic medications and those who were not (16).…”

“…Recently, thyroid nodules have been detected with increasing frequency as the use of ultrasound (US) has increased for evaluating the thyroid gland (1)(2)(3). US-guided fine needle aspiration (US-FNA) biopsy is a safe, accurate, and cost-effective method for the preoperative evaluation of thyroid nodules (2,(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15).…”

“…US-guided fine needle aspiration (US-FNA) biopsy is a safe, accurate, and cost-effective method for the preoperative evaluation of thyroid nodules (2,(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). In addition, US is the most suitable method for evaluation of hemorrhagic complications after the procedure (4,5).…”

“…Minor hematomas and local pain are the most common clinical complications after US-FNA of thyroid nodules (4)(5)(6). However, few published studies have addressed the factors contributing to hematoma formation after US-FNA of thyroid nodules (2,(4)(5)(6)16). Additionally, performing US-FNA in patients taking anticoagu-sent was waived because of the retrospective nature of the study.…”