METHODS IN PATHOLOGY - CYTOLOGIC DIAGNOSIS OF ANAL INTRAEPITHELIAL NEOPLASIA USING SMEARS AND CYTYC THIN-PREPS

To investigate the optimal cytologic method for detecting anal intraep ithelial neoplasia, the quality and diagnostic findings in 117 convent ionally prepared smears and 191 CYTYC Thin-Preps were compared, Sample s were obtained with a dacron swab from subjects participating in a lo ngitudinal study of gay or bisexual men known as the Study to Help the AIDS Research Effort (SHARE). The smear takers were general clinician s who had no experience in obtaining cytologic specimens from the anus . Smears were entirely satisfactory in 48 (41.0%) subjects, limited fo r interpretation in 41 (35.0%), and unsatisfactory in 28 (23.9%). CYTY C preparations were satisfactory in 158 (82.7%) cases and unsatisfacto ry in 33 (17.3%). Insufficient cellularity was the most frequent reaso n for both unsatisfactory smears and CYTYC preparations, but air dryin g artifact was present in nearly every smear. Squamous intraepithelial lesions (SILs) were detected in four (4.5%) smears compared to 53 (33 .6%) CYTYC slides. The detection of SIL correlated with the presence o f glandular and metaplastic cells in CYTYC preparations, but this asso ciation disappeared if only satisfactory specimens were considered, In conclusion, CYTYC Thin-Preps were satisfactory twice as often as conv entional smears (P < 0.005) and detected nearly eight times as many SI Ls (P < 0.005).