COMPARISON OF THINPREP AND CONVENTIONAL PREPARATIONS - NONGYNECOLOGICCYTOLOGY EVALUATION

ThinPrep processing, an automated cytopreparatory method, has been rep orted to show good correlation with conventional preparations and to r educe the rate of false-negative diagnoses. In a retrospective review of 230 consecutive nongynecologic cytology cases, we compare the Thin Prep (TP) method with conventional preparations (CP). There were 129 f ine-needle aspiration (FNA) specimens from various sites, including 51 breasts, 40 thyroids, 14 lungs, 8 livers, and 16 miscellaneous sites. The sources of 101 body cavity fluids included 68 pleural/peritoneal effusions, 25 peritoneal/pelvic washings, and 8 miscellaneous sites. E ach case was evaluated for cellularity, morphologic details, and obscu ring background material. Diagnoses of the TP slides were classified a s insufficient, normal, benign, suspicious, or malignant. Each case wa s then correlated with the tissue diagnosis when available. In TP slid es, cellular arrangements, nuclear details, and nuclear cytoplasmic ra tio were preserved, while blood and diathesis were eliminated. There w as no statistically significant difference between TP and CP in the di agnostic categories. However, in six cases of ''insufficient for diagn osis'' on FNA by CP, TP yielded sufficient cells and tissue fragments for diagnosis. One case each of FNA and body fluid with a diagnosis of ''suspicious for malignancy'' by CP was considered ''positive'' on TP slides. The overall sensitivity of TP was 97.6%, and the specificity was 92.9%. The positive predictive value was 93.0%. We conclude that t he ThinPrep method shows good correlation with conventional preparatio ns in both FNA and body fluids. (C) 1997, Wiley-Liss, Inc.