Specimen adequacy evaluation in gynecologic cytopathology: current laboratory practice in the College of American Pathologists Interlaboratory Comparison Program and tentative guidelines for future practice.
Routine specimen adequacy evaluation, as advocated by The Bethesda System (TBS), can play an important role in improving the sensitivity and accuracy of cervical cytopathology screening. The effectiveness of this measure, however, has been limited by the lack of uniform criteria for adequacy. Practice parameters are now emerging, through TBS development of tentative criteria and interlaboratory comparison of adequacy practices. This study reviews 1) nationwide responses to surveys of laboratory practices in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology (CAP PAP); 2) the definitions of adequacy based on TBS; and 3) the results of implementation of these criteria in a private independent laboratory, university hospital laboratory, and private nonprofit hospital laboratory. In the initial CAP PAP survey in 1990, 35% of responding laboratories routinely reported specimen adequacy, increasing to 66% in 1991 and 85% in 1992. Interlaboratory variations in adequacy practices were observed, however, underscoring the need for consensus criteria. The experience in the authors' laboratories indicates that TBS criteria can serve as a sound guideline. Effective implementation of adequacy assessment in the individual laboratory requires careful attention to ensuring the quality of adequacy ratings, correlating clinical and prior laboratory information, issuing clear and concise reports, and giving recommendations judiciously. Through interlaboratory comparison and consistent intralaboratory emphasis on specimen adequacy, greater uniformity of adequacy assessment can be achieved, and adequacy evaluation can achieve its promise of improving the quality of cervical cytopathology.