大豆蛋白在甲状腺细针穿刺细胞蜡块制备中的应用OA

Objective:Fine-needle aspiration(FNA)is the preferred method for evaluating the nature of thyroid nodules.However,conventional smears have limitations,including limited cellularity,loss of architectural information,and inability to meet the requirements for subsequent immunohistochemical and molecular testing.The cell block technique can compensate for these shortcomings,but existing preparation methods for scant cellular samples are associated with high cell loss,procedural complexity,and increased risk of exogenous contamination.This study aims to evaluate the success rate and clinical application value of a soybean protein-assisted filter paper transfer method for preparing thyroid FNA cell blocks,and to establish a simple,low-cost method capable of effectively enriching scant cellular material,thereby providing a feasible technical solution for primary healthcare institutions. Methods:A total of 80 patients who underwent ultrasound-guided thyroid FNA at the Department of Ultrasound,Yingcheng People's Hospital,from January to October 2025 were retrospectively included.Among them,23(28.8%)were male and 57(71.2%)were female,with an age range of 26 to 88 years and a mean age of 53.9±11.4 years.For each case,both conventional smears and cell blocks were prepared.The cell blocks were produced using a soybean protein-assisted filter paper transfer method:Aspirates were immediately rinsed and fixed,centrifuged to concentrate cells,followed by the addition of soybean protein carrier solution and 95%ethanol.After thorough mixing,the suspension was transferred onto circular filter paper and centrifuged,allowing cell sediment to be effectively retained and completely carried at the bottom of the tube.The sediment was then collected for dehydration,embedding,and sectioning.Evaluation indicators included the success rate of cell block preparation,hematoxylin and eosin(HE)staining quality,and immunohistochemical staining performance.Two senior pathologists independently performed diagnostic classification according to the Bethesda diagnostic system in a double-blind manner.Differences between conventional smears and cell blocks were compared.Cohen's Kappa test was used to assess diagnostic concordance,and the McNemar test(with continuity correction)was applied to compare differences in indeterminate diagnoses(Bethesda categories Ⅲ and Ⅴ),with calculation of χ2 values,P values,paired odds ratios(OR),and 95%confidence intervals(CI).The significance level was set at α=0.05. Results:The success rate of cell block preparation was 96.25%(77/80).In the three failed cases,smear cellularity was<1 000 cells.HE staining showed well-preserved cellular morphology,clear chromatin structure,and distinct nuclear-to-cytoplasmic contrast.The soybean protein background appeared as a uniformly distributed pale red matrix without obscuring target cells.Occasional plant cell debris were easily identifiable and did not interfere with diagnosis.Immunohistochemical staining showed accurate localization and clean background;the expression patterns of cytokeratin 19(CK19),thyroid transcription factor-1(TTF-1),and thyroid peroxidase(TPO)were consistent with those observed in corresponding tissue blocks.The overall diagnostic concordance between the 2 methods was moderate(Kappa=0.532,P<0.001),with complete agreement in 53 cases and an overall concordance rate of 66.25%(53/80).The use of cell blocks reduced the number of indeterminate diagnoses(categories Ⅲ and Ⅴ)from 30 cases in smears to 14 cases,representing a 53.33%reduction(16/30).Notably,62.50%(10/16)of smear-based categoryⅤ(suspicious for malignancy)cases were upgraded to category Ⅵ(malignant)in cell blocks.McNemar test showed a statistically significant difference(χ2=11.250,P<0.001),with a paired OR of 9.000(95%CI 2.160 to 37.480). Conclusion:The soybean protein-assisted filter paper transfer method for preparing thyroid FNA cell blocks demonstrates a high success rate and effectively enriches scant cellular material,with good preservation of cellular morphology and antigenicity.Both HE staining and immunohistochemical staining show satisfactory performance.This method significantly reduces the rate of indeterminate diagnoses in the Bethesda diagnostic system and improves diagnostic certainty in thyroid FNA,providing a reliable platform for subsequent immunohistochemical and molecular testing.