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、重复收集和原发性恶性肿瘤对腹膜液细胞学诊断性能的影响

引言 腹膜液细胞学检查建议体积为 80-200 毫升。当体积受到存在量和疾病因素的限制时，虽然截断是不切实际的，但是可以重复收集。本研究通过将诊断一致性与单个标本的体积、每天收集的总体积以及入院内的体积进行比较，来解决诊断所需的充分性和数量。还调查了在一天内、入院期间和患者一生的整个入院期间重复收集的诊断率。方法 检索超过 27 年的腹膜液细胞学标本，并根据采集日期、入院人数和患者人数进行匹配。回顾病例记录以确定所有恶性腹水病例。结果 总共有 19,392 个标本来自 14,327 个入院和 11 个，共检索089例，确诊为恶性腹水1531例。同一天的细胞学诊断与入院之间的一致性很高 (κ>0.8)。液体体积随细胞学诊断等级的增加而增加 (p<0.001)，体积越大则不一致性越高 (p<0.05)。60-100ml 的标本显示出最好的诊断一致性。为达到 99.5% 的诊断率，需要三个连续等分试样、一次入院中不同两天的收集或一生中三次入院。同一天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 (p<0.001) 恶性肿瘤需要最少的重复诊断。结论 强烈建议不要遗漏实验室提交的任何液体。