Our objective was to determine whether cell blocks (CB) performed on unsatisfactory ThinPrep Pap Test™ residual samples rendered additional clinically significant pathologic findings not detected in the original ThinPrep® Pap smears. One hundred consecutive ThinPrep® Paps categorized as unsatisfactory were selected for this study. The cytologic diagnosis of unsatisfactory was based on lack of cellularity (squamous) or complete obscuring blood or inflammation. Residual PreservCyt™ samples from these consecutive unsatisfactory ThinPrep™ Paps were used to prepare a cell block, using the inverted filter technique. One hematoxylineosin (H&E)-stained slide was prepared and evaluated. The amount and the cellular changes were noted for all smear constituents and compared with the original slides. The average patient age was 32 ± 11 yr. The ThinPrep® Pap was performed as a follow-up on a previous abnormal smear (12%), pregnancy (25%), abnormal bleeding (22%), or previous unsatisfactory ThinPrep® Pap (5%), or as routine screening (36%). Variable amounts of endocervical cells, endometrial cells, and metaplastic cells, as well as a variable number of squamous epithelial cells, were present in 89%, 9%, 50%, and 35% in the CB method vs. ThinPrep®, respectively. Abnormal cellular changes were noted in 15% of patients (9% with LSIL, and 6% with atypia of undetermined significance); 9 patients with squamous dysplasia had a previous abnormal ThinPrep® Pap. A follow-up Pap smear and/or cervical biopsy were performed in 10 of the 15 patients with abnormal cytology detected on CB method revealing: LSIL (1 patient), HSIL (1 patient), ASCUS (1 patient), and within normal limits (7 patients). The findings indicate that the preparation of a CB does not contribute significantly. Importantly, no carcinomas or HSILs were identified on CB preparations. Since a large majority of lesions identified were LSILs, a repeat Pap smear in these cases represented a more cost-effective strategy than cell block preparation, although a cell block preparation may be useful in selected cases.
ASJC Scopus subject areas
- Pathology and Forensic Medicine