Glandular Disease Detection

DESIGN: Although the ThinPrep Pap Test is replacing conventional Pap smears in many clinical practices, experience with the identification of glandular lesions is limited. In this study, ThinPrep cytology of glandular lesions was evaluated in a large, inner city teaching hospital with high rates of glandular abnormality. STUDY DESIGN: Six months of ThinPrep diagnoses in 1998, following nearly 100% conversion of the laboratory to the ThinPrep Pap Test, were compared to January-December 1997 conventional smear diagnoses for glandular disease. Biopsy confirmation was evaluated for these cases. Findings on all biopsy-confirmed glandular cases were also compared to findings on cytology. RESULTS: Similar overall rates of glandular cytology were found. For conventional smears (12 months), 46 cases were diagnosed out of 43,289 smears (0.11%). For ThinPrep cytology (six months), 36 cases were diagnosed out of 25,783 slides (0.14%, P = NS). In the year 1997, 9 biopsy-confirmed conventional smear diagnoses of adenocarcinoma in situ (AIS) or adenocarcinoma were noted versus 10 for six months of 1998 for the ThinPrep method. A statistically significant reduction in the number of miscellaneous nonglandular (squamous) biopsy diagnoses were found with ThinPrep glandular cytology (14 vs. 4 cases, P < .05). For known biopsy-confirmed glandular cases of AIS or adenocarcinoma, a statistically significant reduction in the cytology false negative rate was noted with the ThinPrep method (17 vs. 4 cases, P < .02). CONCLUSION: The ThinPrep method provides more accurate diagnoses of glandular disease, with an increase in both sensitivity and specificity for glandular lesions Abstract BACKGROUND: The ThinPrep Pap Test (TP), a liquid-based cervical cytology preparation, was approved for use in the U.S. in 1996. The purpose of this study was to compare TP performance and biopsy follow-up studies with a similar population of high risk patients sampled by conventional Papanicolaou (Pap) smear (CS). METHODS: Diagnostic and specimen adequacy interpretations for 2727 TP direct-to-vial Pap tests from a high risk university hospital practice were compared with 5000 CS preparations from the same physicians taken 1 year previously. Biopsy follow-up studies for the categories of squamous intraepithelial lesion (SIL), carcinoma, and atypical squamous cells of undetermined significance (ASCUS) for each time period and technique were contrasted. RESULTS: The SIL/carcinoma detection rate increased from 7.7% to 10.5% (P < 0.01) and the ASCUS rate decreased from 12.5% to 6.9% (P < 0.01); the percentage of satisfactory but limited specimens decreased from 19.4% to 10.5% (P < 0.01). Low grade SIL cases increased by 57% (P < 0.01) whereas the 26% increase in high grade SIL cases was not statistically significant. Greater than 90% of ungraded SIL, high grade SIL, and carcinoma cases had abnormal biopsies by both the TP and CS methods. The number of biopsyconfirmed high grade dysplasias and carcinomas was similar in the two groups. A low grade SIL detected by TP was less likely to have an abnormal biopsy (70% vs. 85% for CS). Nevertheless, the 57% increase in low grade SIL diagnoses by TP resulted in more TP patients with dysplastic biopsy diagnoses. Follow-up studies for ASCUS cases diagnosed by either TP or CS were similar, and 21-24% of patients eventually were found to have dysplasia. CONCLUSIONS: The TP technique appears to lead to the increased detection of low grade SIL lesions, decreased satisfactory but limited samples, and fewer equivocal specimens. No increase in biopsy-confirmed high grade dysplasias and carcinomas was found. Follow-up studies for the ASCUS category were nearly identical to those for CS. Ashfaq R, Gibbons D, Vela C, Saboorian MH, Iliya F. Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235-9073, USA. Carpenter AB. Department of Pathology and Laboratory Medicine, University of Kentucky Chandler Medical Center, Lexington, USA. Acta Cytol. 1999 Jan-Feb;43(1):81-5. Cancer. 1999 Jun 25;87(3):105-12. ThinPrep Pap Test. Accuracy for glandular disease. ThinPrep Pap Test: performance and biopsy follow-up in a university hospital.