The number of dyskaryotic cells on an initial ThinPrep® cervical sample showing mild dyskaryosis has predictive value

OBJECTIVES: Recent National Health Service Cervical Screening Programme (NHSCSP) guidelines suggest referral for colposcopy following an initial result of mild dyskaryosis. The aim of this study was to investigate if the number of dyskaryotic cells counted on an initial ThinPrep cervical sample showing mild dyskaryosis has predictive value. METHODS: Cases of mild dyskaryosis on ThinPrep cervical samples from 2002 were retrieved from the cytology department records of St Luke's Hospital. A total of 123 sequential cases with a first-time result of mild dyskaryosis on ThinPrep slides with follow-up cytology available in the same institution were identified. While blinded to outcome, the number of dyskaryotic cells was counted in each case. Follow-up colposcopy/histology information was retrieved where indicated. The number of dyskaryotic cells counted on each slide was collated with outcome data. RESULTS: Of the 123 cases, six women were lost to follow-up. Seventy-three had a negative outcome, 27 had a low-grade outcome and 17 had a high-grade outcome. Only one of 17 high-grade outcome cases had < or = 15 dyskaryotic cells on the initial slide. The distribution of women with a negative/low-grade outcome and those with a high-grade outcome with >15 and < or = 15 dyskaryotic cells on the initial slide was tested using a chi-square test (P = 0.008). The negative predictive value for a high-grade outcome when < or = 15 dyskaryotic cells were present on the initial slide was 97.7%. CONCLUSION: The number of dyskaryotic cells on ThinPrep slides showing mild cervical dyskaryosis has predictive value. The number of dyskaryotic cells may be used to select women suitable for cytological rather than colposcopic follow-up.