Introduction Volume recommendations of 80-200ml have been proposed for peritoneal fluid cytology. While cut-offs are impractical when volume is limited by the amount present and disease factors, collections, however, can be repeated. This study addresses adequacy and number needed to diagnose by comparing diagnostic agreement to volumes in single specimens, total volumes collected daily, and within admissions. The diagnostic yield of repeating collection within a single day, admission, and throughout admissions of a patient’s lifetime was also investigated. Methods Peritoneal fluid cytology specimens over a 27-year period were retrieved, and matched by collection date, admission number and patient number. Case notes were reviewed to establish all cases of malignant ascites. Results In total, 19,392 specimens from 14,327 admissions and 11,089 patients were retrieved, with 1,531 patients confirmed with malignant ascites. Agreements between cytologic diagnoses within the same day and admission were high (κ>0.8). Fluid volume increased with grade of cytologic diagnosis (p<0.001), and greater volume was associated with higher discordance (p<0.05). Specimens of 60-100ml showed the best diagnostic concordance. To achieve a 99.5% diagnostic rate, three sequential aliquots, collections from two different days in an admission, or three admissions within a lifetime is required. The diagnostic yield of one aliquot within batches from the same day was only 88.9%. Gastrointestinal (p=0.040), gynecologic (p=0.005) and lung (p<0.001) malignancies required the least repeats for diagnosis. Conclusions Omission of any fluid from laboratory submission is strongly discouraged. As a simple rule, three repeats are necessary for excluding malignant ascites.


中文翻译：

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诊断恶性腹水所需的数量——体积、重复采集和原发性恶性肿瘤对腹膜液细胞学诊断性能的影响

简介 对于腹膜液细胞学检查，建议体积为 80-200ml。虽然当数量受到存在数量和疾病因素的限制时，截断是不切实际的，但是，可以重复收集。本研究通过比较单个标本体积、每日收集的总体积和入院内的诊断一致性来解决诊断所需的充分性和数量。还调查了患者一生中在一天内、入院以及整个入院过程中重复采集的诊断率。方法检索27年的腹腔液细胞学标本，并按采集日期、入院号和患者号进行匹配。审查病例记录以确定所有恶性腹水病例。结果 共回收14,327例入院标本、11,089例患者19,392份标本，其中1,531例确诊为恶性腹水。当日细胞学诊断与入院之间的一致性很高（κ>0.8）。液体量随细胞学诊断分级而增加（p<0.001），液体量越大，不一致程度越高（p<0.05）。60-100ml的标本显示出最佳的诊断一致性。为了实现 99.5% 的诊断率，需要连续进行 3 次等分、一次入院时不同日期的收集或一生中 3 次入院的收集。同日批次内一份等分试样的诊断率仅为 88.9%。胃肠道 (p=0.040)、妇科 (p=0.005) 和肺部 (p<0.001) 恶性肿瘤需要最少的重复诊断次数。结论 强烈建议不要在实验室提交中遗漏任何液体。作为一个简单的规则，需要重复 3 次才能排除恶性腹水。