The multiple facets of ovarian high grade serous carcinoma: A review on morphological, immunohistochemical and molecular features.

High-grade serous ovarian carcinoma (HGSOC) is the most aggressive subtype of epithelial ovarian cancer and a leading cause of mortality among gynecologic malignancies. This review aims to comprehensively analyze the morphological, immunohistochemical, and molecular features of HGSOC, highlighting its pathogenesis and identifying biomarkers with diagnostic, prognostic, and therapeutic significance. Special emphasis is placed on the role of tumor microenvironment (TME) and genomic instability in shaping the tumor's behavior and therapeutic vulnerabilities. Key advancements, such as the identification of TP53 and BRCA mutations, the classification of homologous recombination repair (HRR) deficiencies, and the clinical implications of biomarkers like folate receptor alpha (FRα) and PD-L1 are discussed. These findings reveal actionable insights into targeted therapies, including immune checkpoint inhibitors and PARP inhibitors, which hold promise for improving outcomes in HGSOC. This synthesis of knowledge aims to bridge gaps in understanding HGSOC's multifaceted biology, enhance clinical decision-making, and foster the development of precision therapies.