The unsatisfactory ThinPrep® Pap Test™: analysis of technical aspects, most common causes, and recommendations for improvement.

ThinPrep® preparation is a widely-used method for processing gynecologic specimens due to the many advantages of the technique. However, the presence of blood, inflammation, and lubricant, among other factors, can significantly interfere with specimen adequacy. The aim of this study was to identify and overcome the most common reasons for unsatisfactory ThinPrep® Pap Test™ results in our laboratory. From October 2010 to January 2011, we reprocessed cases categorized as "unsatisfactory for evaluation" to determine whether reprocessing these specimens would impact the unsatisfactory rate. Reasons for unsatisfactory results were classified as: technical reasons, scant cellularity, and complete obscuring factors. Two hundred fifty-three cases were initially classified as unsatisfactory. Of these, 226 cases were reprocessed. Ninety cases became satisfactory after reprocessing with an overall improvement of 40%. The most common reasons for unsatisfactory results were the presence of lubricant (96 cases), presence of blood (64 cases), and technical problems (33 cases). Cases affected by blood or technical issues showed a significant improvement after reprocessing (56.2% and 90.9%, respectively). However, unsatisfactory cases owed to the presence of lubricant showed a relatively low percentage of improvement (16.6%). The main reasons for unsatisfactory results, the presence of blood and lubricant, can be avoided in many cases if sampling is not performed during bleeding and if the use of lubricants is limited during sample collection. Our study showed that reprocessing of selected cases can improve the overall unsatisfactory rate and can potentially reduce the risk of missing significant lesions.