**Abstract**

Ovarian tumours are a heterogeneous group of neoplasms classified based on histopathologic type and grade of differentiation. They comprise a broad range of tumours from benign and borderline to malignant histotypes characterised by different histopathological, immunophenotypic and molecular features. The purpose of this chapter is to present an overview of the recent advances in the ovarian epithelial malignant tumours classification along with the histopathological, immunophenotypic and molecular diagnostic criteria highlighting areas of terminology discrepancies or changes and diagnostic challenges. These changes provide a better understanding of the ovarian tumours nature and lead to a more efficient therapeutic management of these pathological entities.

**Keywords:** ovarian cancer, histopathology, immunophenotype, molecular pathology
