[Histological grading of epithelial ovarian cancer. Review and recommendation]

Histological grading of ovarian cancer has prognostic relevance and implications for treatment decisions. No standardized grading system has been established so far. Several grading systems are currently being used, including the FIGO, WHO, and Silverberg grading systems which cannot be directly translated into each other. Furthermore, individual grading criteria are not uniformly applicable to different histological subtypes. For serous ovarian cancer a binary grading system is now in use as the distinction between low-grade versus high-grade carcinomas reflects the different pathogenesis of these entities. Uniform guidelines for grading ovarian cancer are necessary and should ideally reflect the prognosis. This article provides an overview of commonly used grading systems and their prognostic value. The article demonstrates that a type-specific grading of ovarian cancer should be performed and recommendations for grading the various histological subtypes are given.