Reliability of histopathologic diagnosis of cervical intraepithelial neoplasia

A study was designed to measure the inter-pathologist consistency of histopathologic diagnosis of cervical intraepithelial neoplasia (CIN) among four pathologists. Intra-pathologist reliability over time was also determined. Between-pathologist comparisons resulted in agreement only 50% of the time; however, 81% of pairs were within one CIN grade of each other. Seventy-one percent of first and second diagnoses of the same pathologist were identical and 93% of pairs were within one CIN grade. In seven cases, however, pairs of evaluations of the same slide were remarkably disparate, two considered normal and CIN III by the same pathologist at different times. The findings of this study, using the CIN grading system, are consistent with other studies using different classification schemes. Inconsistency of diagnoses and discrepancies between pathologists must be considered when conservative therapy is elected for a patient with cervical intraepithelial neoplasia.