Comparison of Number of Passes and Cytopathological Specimen Adequacy for Thyroid Fine-Needle Aspiration Biopsy in the Absence of an On-Site Pathologist

Abstract

Aim: Ultrasound-guided fine-needle aspiration biopsy (FNAB) is a reliable, minimally invasive diagnostic method with high sensitivity and specificity in the evaluation of thyroid nodules. Our aim in this retrospective study was to determine if there was a difference in the adequacy ratio based on the number of needle passes in the thyroid FNABs in the absence of rapid on-site evaluation (ROSE) by the pathologist and to determine the optimal needle pass number for FNAB. Methods: Between November 2018 and February 2019, thyroid FNABs of 121 (99 female, 22 male) patients were evaluated retrospectively. Samples for each biopsy were numbered according to the order of retrieval, and 4 pairs of slides were prepared by the radiologist without on-site microscopic evaluation. Cytological results were determined according to the Bethesda classification. Results: The rate of adequacy in the first, second, third, and fourth passes were 76.0, 82.6, 77.7, and 71.2%, respectively. No statistically significant difference was found between these four groups in terms of adequacy (p = 0.21). The adequacy rates of the 1st, 1st+2nd, 1st+2nd+3rd, and cumulative evaluation of all four biopsies were 76.0, 87.6, 90.1, and 91.7%, respectively (p = 0.001). A statistically significant difference was found in the comparison of the 1st biopsy and the cumulative 1st+2nd biopsy in terms of adequacy rates (p = 0.019). However, there was no statistically significant difference between the cumulative 1st+2nd biopsy and the cumulative 1st+2nd+3rd biopsy in terms of adequacy rates (p = 0.54). Conclusions: In cases where ROSE cannot be performed, we recommend a minimum of 2 and a maximum of 3 needle entries for FNAB adequacy with the right technique and preparation.

Analysis of intra‐observer and inter‐observer variability of pathologists for non‐benign thyroid fine needle aspiration cytology according to Bethesda system categories

“…For these reasons, the distinction between category III and other non‐benign nodules becomes important. Although the category III rating is recommended to be below 7% in a thyroid biopsy series reported according to the TBSRTC classification, this rate continues to be as high as 20 to 34% in some series 13,18 . In our study, there was a significant difference between category III AUS/FLUS rates (7.3 vs 28.0%) in the initial evaluation of pathologists (Table 1).…”

“…Evaluations of thyroid nodule biopsies were performed according to the TBSRTC system as previously described 13 . The first pathology results of the included nodules were noted.…”

“…All thyroid nodule biopsies were performed under ultrasound (US) guidance by the same radiologist described previously, without a rapid on‐site evaluation 13 …”

Needle tract seeding of papillary thyroid carcinoma after fine-needle capillary biopsy: A case report

“…, FNCB) with a 23-G or a smaller fine needle are recommended[ 14 , 15 ]. In any case, an excessive number of passes should be avoided[ 16 ].…”

Ultrasound‐guided fine‐needle aspiration biopsy of thyroid nodules

“…Perform two to four passes, or until you have at least one adequate smear without contamination. It is preferable to have a cytopathologist available for immediate review of the slides, otherwise, let these air dry (or immediately fix the smears in alcohol if your cytopathology laboratory uses Papanicolaou stain) and keep them at room temperature 10 . Instead of smears, the sample material (especially if pure cystic material is aspirated) may be obtained in a collecting tube and sent for other cytopathology techniques, such as cell blocking.…”