High-Score US-Suspicious Subcentimeter Thyroid Nodules: What Factors Affect Adequate Sampling of US-Guided Fine-Needle Aspiration Biopsy?

Abstract

Background. Fine-needle aspiration biopsy (FNAB) is diagnostic standard for thyroid nodules. However, the influence of adequate sample rate of US-guided FNAB for subcentimeter thyroid nodules is not known well. Objectives. To assess the factors affecting adequate sample rate of US-guided FNAB for subcentimeter thyroid nodules. Methods. Three hundred and forty-nine consecutive US-guided FNAB procedures were performed in 344 patients with subcentimeter thyroid nodules. The adequate sample rate was analyzed for all nodules on the basis of nodule-related and technical factors. The factors affecting adequate sample rate of US-guided FNAB for subcentimeter thyroid nodules were determined by multivariate logistic regression. Results. The adequate sample rate increased with larger nodules (72.7% for 3–6 mm nodules and 84.9% for 7–10 mm nodules (P=0.007)). The adequate sample rate was 63.9%, 81.3%, and 90.6% in nodules with macrocalcifcation, microcalcification, and no calcification, respectively (P<0.001). The adequate sample rate was 71.8% for biopsies performed with a perpendicular needle path and 85.0% with a parallel needle path (P=0.004). The significant factors affecting adequate sample rate of US-guided FNAB for subcentimeter thyroid nodules were nodule size (P<0.001; odds ratio (OR) for 7–10 mm nodules was approximately 3.0 times higher than that for 3–6 mm nodules), calcification (P<0.001; OR for nodules without calcification was approximately 5.3 times higher than that for the nodules with macrocalcification), and needle path (P=0.044; OR for the use of the parallel needle path was about 1.8 times higher than that for the perpendicular needle path). Conclusion. Nodule size, calcification, and needle path were the determinants of sample adequacy. The adequate sample rate was higher in larger nodules, in nodules without calcification, and upon using a parallel needle path for biopsy.

Influence of maximum diameter on fine-needle aspiration biopsy outcomes in ACR TI-RADS 5 thyroid nodules

“…Similarly, studies by Leenhardt et al., Leung et al., Li et al., and Chen et al. observed a comparable relationship in FNA for thyroid nodules ( 10 , 18 , 28 , 29 ). Conversely, other studies found no significant correlation between nodule MD and sample adequacy in FNA ( 12 , 15 , 30 , 31 ).…”

“…Besides MD, numerous studies have identified various factors potentially influencing FNA outcomes in thyroid nodules ( 10 , 12 – 16 , 18 , 28 – 30 , 32 , 33 ), including age ( 14 ), needle path ( 18 ), needle size ( 11 ), calcification ( 10 , 12 , 18 ), echogenicity ( 14 , 16 ), composition ( 13 ), shape ( 12 ), the depth of nodule ( 29 , 30 ), and Hashimoto thyroiditis ( 12 ) et al. However, these studies primarily focused on factors influencing non-diagnostic outcomes (Bethesda I or III), with few examining the potential factors impacting malignant outcomes in FNA of thyroid nodules.…”

Contrast-enhanced ultrasound improves the potency of fine-needle aspiration in thyroid nodules with high inadequate risk

“…Thyroid nodules with high inadequate risk have a significantly higher inadequate rate after US-FNA in our study, comparing with the overall 3748 nodules in our center (16.7% vs. 6.6%, P < 0.001) or some other centers [ 17 ]. They have some common US features, such as high cystic composition, mixed cystic and solid nodules with hemorrhage, or suspicious degenerating nodules [ 4 , 6 ]. For instance, the inadequate rates of US-FNA in cystic, predominantly cystic, predominantly solid and solid subgroups are 28.1%, 17.1%, 10.0% and 9.2% ( P = 0.019), which indicating that the amount of cystic component is an important factor affecting specimen adequacy.…”

“…It is reported that composition of thyroid nodules has a definite effect on acquiring specimen during US-FNA. Thyroid nodules with high cystic component [ 4 , 5 ], hemorrhage or with macrocalcification [ 6 ] have higher risk of specimen inadequacy [ 7 ]. Meanwhile, solid nodule undergo reduction in size, which is known as degenerating nodules with malignant US features, often result in lower specimen acquisition [ 8 , 9 ].…”

Update on the Evaluation of Thyroid Nodules

“…However, in clinical practice, many patients prefer not to forego further evaluation and insist on proceeding with FNAB. Sample adequacy represents an important issue with FNAB sampling of subcentimeter nodules and has been reported to be as low as 72.2% for 3-to 6-mm nodules, 84.9% for 7-to 10-mm nodules, and 63% in the presence of macrocalcifications (60). TSH suppression therapy to shrink TN in euthyroid individuals was in vogue for many years, and a metaanalysis published in 2005 found an 88% likelihood of achieving a reduction in nodule volume of greater than compared with placebo or no treatment (61).…”