Currently histopathological review is not standard practice in clinical studies of ovarian carcinomas. Published retrospective analyses as well as own unpublished observations have indicated that a certain percentage of study patients may have ovarian lesions other than ovarian carcinomas which may be in conflict with study inclusion criteria. In this context, the distinction of ovarian carcinomas from borderline tumors, ovarian metastases, and sex cord tumors has been shown to be a potential pitfall. In cases of incorrect diagnoses, non-beneficial morbidity at unnecessary high cost may occur, in other instances, more adequate therapeutic modalities might be withheld from a patient. At present, the concept of a central histopathology review for patients with ovarian carcinomas is being studied prospectively in a translational research project of the AGO-Ovar termed "HIstologische STandardisierte Zweitbegutachtung in einem Studienkollektiv fortgeschrittener Ovarialkarzinome, OVAR 11t-HISTO" (Histological standardized review in a study collective of advanced ovarian cancer; http://www.mh-hannover.de/institute/pathologie/dgp:Studien).