Khan Shehnaz, Omar Tanvier, Michelow Pamela
Department of Anatomical Pathology, Division of Cytopathology, National Health Laboratory Service, Johannesburg, South Africa.
J Cytol. 2012 Jul;29(3):177-82. doi: 10.4103/0970-9371.101167.
One of the constraints of the conventional FNA smear is the limited material available for adjuvant diagnostic investigations including immunocytochemistry. The cell block technique employs the retrieval of small tissue fragments from a FNA specimen which are processed to form a paraffin block. It is widely accepted that cell block technique increases the cellular yield and improves diagnostic accuracy. The ability to obtain numerous tissue sections allows for multiple immunostains and other studies to be performed akin to paraffin sections produced in histopathology.
To determine the effectiveness of the cell block technique by comparing cytomorphological preservation and immunocytochemistry (ICC) stains on paired cell block and conventional fine needle aspiration (FNA) samples.
In this prospective study, material for both glass slides and cell blocks were collected simultaneously during fine needle aspirates from 47 samples comprising lung and liver masses. Grading of cellularity, morphological preservation, architectural preservation, immunocytochemical staining intensity and presence of background staining on paired FNA smears and cell block samples were compared. Each arm of the paired analysis was performed blindly without knowledge of the grading outcome of the other. The Kappa statistic (κ) was used to measure inter-rater agreement.
The 47 samples evaluated included FNAs from the lung, 24/47 (51%) and liver, 23/47 (49%). The immunocytochemistry stains consisted of 44/47 (94%) CK7; 44/47 (94%) CK20; 18/47 (38%) TTF1; 10/47 (21%) synaptophysin; 10/47 (21%) Hepar-1 and 7/47 (15%) AE1/3. There was no overall agreement in preservation of cytomorphological detail and ICC staining between the two methods. The Papanicolaou-stained conventional FNA smears fared better than the cell block for the evaluation of nuclear and morphologic characteristics. The ICC stains worked better on the cell block samples due to lack of background and aberrant staining.
Direct FNA smears and cell blocks complement each other and our results indicate that both are needed in the diagnostic work-up of patients. The cost implications of performing both techniques on all FNA material warrants further evaluation.
传统细针穿刺抽吸（FNA）涂片的局限性之一是可用于辅助诊断检查（包括免疫细胞化学）的材料有限。细胞块技术采用从FNA标本中获取小组织碎片，将其处理后制成石蜡块。人们普遍认为，细胞块技术可提高细胞产量并提高诊断准确性。获得大量组织切片的能力使得能够进行多种免疫染色和其他类似于组织病理学中石蜡切片的研究。
通过比较配对的细胞块和传统细针穿刺抽吸（FNA）样本的细胞形态学保存和免疫细胞化学（ICC）染色，确定细胞块技术的有效性。
在这项前瞻性研究中，在对47例包括肺和肝肿块的样本进行细针抽吸时，同时收集用于玻片和细胞块的材料。比较配对的FNA涂片和细胞块样本的细胞密度分级、形态学保存、结构保存、免疫细胞化学染色强度和背景染色情况。配对分析的每个部分在不知道另一部分分级结果的情况下进行盲法操作。使用Kappa统计量（κ）来衡量评分者间的一致性。
评估的47个样本包括来自肺的FNA，24/47（51%）和来自肝的FNA，23/47（49%）。免疫细胞化学染色包括44/47（94%）CK7；44/47（94%）CK20；18/47（38%）TTF1；10/47（21%）突触素；10/47（21%）Hepar-1和7/47（15%）AE1/3。两种方法在细胞形态学细节保存和ICC染色方面没有总体一致性。在评估核特征和形态特征方面，巴氏染色的传统FNA涂片比细胞块表现更好。由于没有背景和异常染色，ICC染色在细胞块样本上效果更好。
直接FNA涂片和细胞块相互补充，我们的结果表明，在患者的诊断检查中两者都需要。对所有FNA材料同时进行这两种技术的成本影响值得进一步评估。
