Department of Cytology and Gynaecological Pathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Acta Cytol. 2022;66(1):72-78. doi: 10.1159/000519336. Epub 2021 Oct 29.
Cell blocks (CBs) are an essential adjunct in cytopathology practice. The aim of this study was to compare 2 techniques of CB preparation - plasma thrombin (PT) method with sodium alginate (SA) method for overall cellularity, morphological preservation, obscuring artefacts, immunocytochemistry (ICC), suitability for molecular analysis, and cost of preparation.
A total of 80 fine-needle aspirates from various sites and serous effusion samples were included. Of these cases, by random selection, 40 each were prepared by PT method and SA methods, respectively. The haematoxylin-eosin-stained sections from the formalin-fixed, paraffin-embedded CBs from both methods were evaluated in a blinded fashion by 2 cytopathologists and scored for cellularity, artefacts, and morphological preservation and analysed by χ2 test with Yates correction. We evaluated 6 cases from each method by ICC for a range of membrane, cytoplasmic and nuclear marker expression. DNA was extracted from four cases to evaluate their utility for molecular analysis.
CB sections from PT and SA techniques showed comparable cellularity and excellent cytomorphological preservation. Blue gel-like artefacts were common in the SA technique but did not interfere with morphological evaluation. ICC staining results were also similar. DNA yield and utility for PCR were also comparable. The SA-CB cost half that of PT-CB (USD 0.4 vs. USD 1).
SA technique of CB preparation is an excellent low-cost alternative to PT method for CB preparation.
细胞块（CBs）是细胞病理学实践中的重要辅助手段。本研究旨在比较两种 CB 制备技术——血浆凝血酶（PT）法和海藻酸钠（SA）法的总体细胞数量、形态保存、模糊伪影、免疫细胞化学（ICC）、分子分析的适用性以及制备成本。
共纳入 80 例来自不同部位的细针抽吸物和浆膜腔积液样本。这些病例中，通过随机选择，分别用 PT 法和 SA 法各制备 40 例。用甲醛固定、石蜡包埋的 CB 制作的苏木精-伊红染色切片由 2 位细胞病理学家进行盲法评估，并对细胞数量、伪影和形态保存进行评分，采用卡方检验（Yates 校正）进行分析。我们用 ICC 对两种方法的 6 例进行评估，评估范围包括膜、细胞质和核标记物的表达。从 4 例中提取 DNA，以评估其在分子分析中的应用。
PT 和 SA 技术的 CB 切片显示出相似的细胞数量和良好的细胞形态保存。SA 技术中常见蓝色凝胶样伪影，但不影响形态学评估。ICC 染色结果也相似。DNA 产量和 PCR 的适用性也相当。SA-CB 的成本仅为 PT-CB 的一半（0.4 美元与 1 美元）。
SA 法是一种用于 CB 制备的低成本替代方法，与 PT 法相比，该方法制备的 CB 效果同样出色。
