Body fluid microscopy in US laboratories. Data from two College of American Pathologists surveys, with practice...

Questionnaires addressing laboratory practices in cerebrospinal fluid and body fluid (serous, synovial) microscopy were distributed to participants in the Clinical Microscopy Survey of the College of American Pathologists, Northfield, Ill, in 1985 and 1989. In both Surveys, cell enumeration was performed primarily by hemocytometry, while nearly all respondents used Wright-stained microscopy. There was little formal quality control to assess the accuracy of counts or differential cell count. Less than 55% of laboratories used the cytocentrifuge. About half of respondents performed a differential cell count on every sample. Slides with atypical or malignant cells were usually (> 85%) reviewed by physicians without automatic referral to the cytopathology section. Only about half of respondents examined every synovial fluid specimen with polarized microscopy for crystals. Other than a modest increase in use of the cytocentrifuge, the 1989 Survey showed little interval change in practices. In 1989, there was equal dependence on Wright's and Papanicolaou's stains for an infrequent diagnosis of malignancy. The low rate of positives may have related to the high prevalence of wedge smears, a suboptimal technique. The Hematology and Clinical Microscopy Resource Committee of the College of American Pathologists makes recommendations for optimal laboratory handling of body fluid specimens for microscopy.