Intraobserver and interobserver reproducibility of WHO and Gleason histologic grading systems in prostatic adenocarcinomas.

In this study a total of 96 patients with prostatic carcinoma were evaluated retrospectively. Sections prepared from paraffin blocks were examined and all cases were scored according to the World Health Organization (WHO) and Gleason grading systems. We investigated intraobserver and interobserver reproducibility of two grading systems in prostatic adenocarcinomas. In our study the intraobserver reproducibilities of the WHO and Gleason systems were 75.0% and 78.1%, respectively. The interobserver reproducibilities of the WHO and Gleason grading systems were 60.4% and 70.8%, respectively. While there was no difference between intraobserver and interobserver variations in the Gleason system (p > 0.05), there was significant difference between intraobserver and interobserver variations in the WHO system (p < 0.05).