Reproducibility and Prognostic Performance of the 1973 and 2004 World Health Organization Classifications for Grade in Non-muscle-invasive Bladder Cancer: A Multicenter Study in 328 Bladder Tumors

Reproducibility of the WHO 2004 and WHO 1973 classification for grade are poor. Scoring of individual criteria is poorly reproducible, suggesting that descriptions of these criteria for grade are not specific. The prognostic value of both the WHO 1973 and the WHO 2004 differ per pathologist.