Layfield L J, Mooney E E, Glasgow B, Hirschowitz S, Coogan A
Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Cancer. 1997 Feb 25;81(1):16-21. doi: 10.1002/(sici)1097-0142(19970225)81:1<16::aid-cncr5>3.0.co;2-e.
The false-negative diagnosis is a major clinical concern and a significant cause of litigation in fine-needle aspiration cytology of breast lesions. A significant number of false-negative diagnoses may be due to inadequate sampling of these lesions. Little information is available in the literature about what constitutes an adequate specimen, and the few publications that address this issue propose criteria based on anecdotal information. Recommendations vary widely and may or may not take clinical findings into account.
The authors studied a subgroup of 183 cases with known outcome, drawn from a series of 1779 cases, to determine the minimum number of cell clusters necessary to ensure that adequate cellular material was present for accurate diagnosis. The series included 21 cases cytologically diagnosed as false-negative, 75 cases that had been correctly identified as benign, 47 cases cytologically designated as atypical, and 40 cases that on initial review had been correctly identified as malignant. In semiblind fashion, the smears from each case were assigned to low, medium, and high cellularity categories. Low cellularity was defined as 10 or fewer cell clusters, moderate cellularity was defined as 11-30 clusters, and high cellularity was defined as more than 30 clusters. A cell cluster was defined as five or more cells. Within the low cellularity group, exact numbers of cell clusters and the presence of individual cells were recorded. The presence of bipolar cells was used as an adjunct criterion for specimen adequacy, and the bipolar cells in each of 10 x 200 fields were counted. Cellularity was then correlated with diagnostic accuracy.
Using a cutpoint of a cumulative score of 6 or more cell clusters or the prominence of bipolar cells (> or = 10 in each of 10 medium-power, x200 fields) for assessment of specimen adequacy, a false-negative rate of 1.5%, associated with an unsatisfactory rate of 20.2%, was obtained.
Based on the data gathered in this study, the authors believe that the sampling false-negative and unsatisfactory rates can be minimized by selecting a cutpoint for satisfactory smears at a level of 6 or more cell clusters (cumulative total) or the presence > or = 10 intact bipolar cells per 10 medium-power fields (x200). Use of these criteria will decrease the false-negative rate of sampling in epithelial lesions of the breast. A false-negative rate of approximately 1.5% was obtained in association with an unsatisfactory rate of 20.2%. Using a cutpoint of 1 or more cell clusters, a false-negative rate of 2.1%, associated with an unsatisfactory rate of 13.7%, was obtained.
在乳腺病变细针穿刺细胞学检查中，假阴性诊断是一个主要的临床问题，也是引发诉讼的重要原因。大量假阴性诊断可能是由于对这些病变的取样不足。关于什么构成足够的标本，文献中几乎没有相关信息，少数涉及此问题的出版物提出的标准是基于轶事性信息。建议差异很大，可能考虑也可能不考虑临床发现。
作者从1779例病例中选取了183例已知结果的亚组病例，以确定确保有足够细胞材料用于准确诊断所需的最小细胞团数量。该系列包括21例细胞学诊断为假阴性的病例、75例被正确鉴定为良性的病例、47例细胞学上被指定为非典型的病例以及40例初次检查时被正确鉴定为恶性的病例。以半盲方式将每个病例的涂片分为低、中、高细胞密度类别。低细胞密度定义为10个或更少的细胞团，中等细胞密度定义为11 - 30个细胞团，高细胞密度定义为超过30个细胞团。一个细胞团定义为五个或更多细胞。在低细胞密度组中，记录细胞团的确切数量和单个细胞的存在情况。将双极细胞的存在作为标本充足性的辅助标准，并对10个×200视野中的每个视野中的双极细胞进行计数。然后将细胞密度与诊断准确性相关联。
使用累积6个或更多细胞团的分数或双极细胞突出（10个中等放大倍数×200视野中每个视野≥10个）作为评估标本充足性的切点，获得了1.5%的假阴性率，不满意率为20.2%。
基于本研究收集的数据，作者认为通过选择满意涂片的切点为6个或更多细胞团（累积总数）或每10个中等放大倍数视野（×200）中存在≥10个完整双极细胞，可以将取样假阴性率和不满意率降至最低。使用这些标准将降低乳腺上皮病变的取样假阴性率。获得了约1.5%的假阴性率，不满意率为20.2%。使用1个或更多细胞团的切点，获得了2.1%的假阴性率，不满意率为13.7%。
