Factors Influencing the Reliability of Thyroid Fine-Needle Aspiration: Analysis of Thyroid Nodule Size, Guidance Mode for Aspiration and Preparation Method

Abstract

Objective: We aimed to clarify the influence of ThinPrep preparation, nodule size and guidance mode on the accuracy of thyroid fine-needle aspiration (FNA). Methods: A total of 1,240 thyroid FNAs were reviewed and 489 cases with histological correlations were enrolled in this study. Results: Of the 489 total cases examined, 101 were processed with both ThinPrep and conventional preparation and 388 entirely with ThinPrep. The overall nondiagnostic rate, sensitivity and accuracy of FNA were 2.0, 91.0 and 89.4%, respectively. The cases with a preoperative ultrasound (n = 469) were grouped according to nodule size. The nondiagnostic rate, sensitivity and accuracy of FNA did not differ significantly with nodule size (p1 = 0.339, p2 = 0.179, p3 = 0.119). A total of 101 resections were performed with palpation-guided FNA and 388 were performed with ultrasound-guided FNA. The nondiagnostic rates, sensitivity and accuracy of FNA were similar in these two groups. Conclusions: The ThinPrep technique is a valid method for thyroid FNA and is effective for thyroid nodules ≥0.5 cm. The reliability of FNA results is not reduced with larger nodules. The use of palpation-guided FNA for palpable solid nodules is also effective.

Size and Ultrasound Features Affecting Results of Ultrasound‐Guided Fine‐Needle Aspiration of Thyroid Nodules

“…Ultrasound (US)‐guided fine‐needle aspiration (FNA) has been acknowledged as the reference standard for the initial diagnosis of thyroid nodules . This technique is generally more accurate and cost‐effective than palpation‐guided FNA . Even in pediatric thyroid nodules, US‐guided FNA is safe and well tolerated .…”

“…Factors affecting FNA results include the nodule size, tumor type, US features, operator experience, number of passes needed for FNA, and experience available for cytologic interpretation . When operator experience and cytologic interpretation are excluded, size is one of the most important factors affecting the sensitivity and positive predictive value (PPV) . For large nodules (>40 mm) and tiny nodules (≤5 mm), nondiagnostic and false‐negative FNA results remain a problem .…”

“…When operator experience and cytologic interpretation are excluded, size is one of the most important factors affecting the sensitivity and positive predictive value (PPV) . For large nodules (>40 mm) and tiny nodules (≤5 mm), nondiagnostic and false‐negative FNA results remain a problem . Another factor affecting FNA is the US appearance of the nodule, although the exact features predicting diagnostic results are not fully characterized.…”

“…Previous studies have been subject to limitations and a degree of bias. Some studies defined benign and nondiagnostic FNA results as “negative.” Some studies involved cases without pathologic evidence, which might overestimate the sensitivity and specificity . The purpose of this study was to evaluate US‐guided FNA according to nodule size with a large population of histopathologically proven cases.…”

Accuracy of non-ultrasound guided thyroid gland fine needle aspiration with biopsy

“…Otolaryngol Rhinol 4(1): 011-014. DOI: http://doi.org/10.17352/2455-1759.000066 achieved in an outpatient setting by a single practitioner with the assistance of an attending pathologist [7]. The comparative reliability of these two methods (i.e., USFNAC vs. FNAC) for thyroid lesion diagnoses has not been extensively studied [8].…”