Individual specimen triage of effusion samples: an improvement in the standard of practice, or a waste of resources?

The standard of practice in cytopathology does not include an individual specimen triage (IST) for sample optimization, but rather prescribes a uniform procedure, e.g., for smears, cell blocks, and cytospins. IST requires additional resources. We sought to evaluate whether IST would result in enhanced diagnostic accuracy and specimen turnaround time in effusions. In order to evaluate the efficacy of IST, 50 effusion samples (31 pleural, 16 peritoneal, and 3 pericardial), each with a minimum volume of 50 ml, were utilized. Each sample was prepared via IST to include at least two initial prepared Diff-Quik-stained cytospins on which the IST was based, as well as a standard cytopreparation protocol for nontriaged samples (NTS) which was limited to 3 smears (2 Papanicolaou-stained, and 1 Diff-Quik-stained) and a hematoxylin-eosin (H&E)-stained cell block section. All triaged and NTS were reviewed retrospectively to determine if IST offered any advantages over the standard cytopreparation protocol for effusion samples. Each was evaluated for diagnostic concordance, turnaround time for final diagnosis, and optimal preparation. In 46 cases, diagnoses in IST and NTS were 100% concordant. Four cases showed minor discrepancies between the original and the NTS diagnoses. In general, the discordant cases were due to sparse cellularity in a specimen composed largely of blood. There was no difference in turnaround time for final diagnosis. Based on a review of all samples, the combination of cell block preparation and cytospins (stained with Diff-Quik and Papanicolaou stains) were considered optimal for microscopic evaluation. IST offers no practical advantage over the NTS standard specimen preparation in relation to the accuracy of final diagnosis or turnaround time. The lysing of grossly bloody fluids with subsequent preparation of cytospins yielded superior preparations for microscopic evaluation over NTS. The standard preparation of effusion samples should include the preparation of a cell block, and cytospins stained with Diff-Quik and Papanicolaou stains, for optimal microscopic evaluation. Copyright 1999 Wiley-Liss, Inc.