Context: Characteristic cytologic features have been identified that distinguish cases that are always identified from those that are sometimes missed in the College of American Pathologists Gynecologic Cytology Program for a variety of different lesions and preparations.
Objective: To compare the cytologic features of cases of squamous cell carcinoma in conventional smears that perform poorly and well.
Design: The cytologic features of 8 conventional smear cases of squamous cell carcinoma that performed poorly in the College of American Pathologists Interlaboratory Comparison Program were compared with 17 cases that performed extremely well.
Results: A total of 2387 individual interpretations were recorded. Of the 86 incorrect responses, 6.2% were for repair, and 0.8% were for Trichomonas. Cases that performed well were significantly more likely to have greater than 1000 dysplastic cells (16/17 vs 4/8, P = .02) and be keratinized (13/17 vs 1/8, P = .007). Obscuring inflammation and cell size were not significant.
Conclusion: Conventional smears with a diagnosis of squamous cell carcinoma that were always identified were significantly more likely to have greater than 1000 cells and be keratinized than cases that performed poorly.