Validation of the Histologic Grading for Ovarian Clear Cell Adenocarcinoma: A Retrospective Multi-institutional Study by the Japan Clear Cell Carcinoma Study Group

Abstract
"Pathologic slides from 150 patients with clear cell adenocarcinoma from the collaborating institutions were reviewed independently by 2 pathologists, and each tumor was graded histologically using the Shimizu-Silverberg and International Federation of Gynecology and Obstetrics (FIGO) grading systems...................... These results suggest that the 2 tested grading systems have limited value for the prognostication of patients with clear cell adenocarcinoma, and that a more effective grading system for this tumor may be required."