Comparative Molecular and Genetic Landscape of Gonadal Germ Cell Tumors: Insights from Testicular and Ovarian Neoplasms

Background/Objectives: Gonadal germ cell tumors (GCTs) arise in the testis and ovary from primordial germ cells. Despite shared origins, they display distinct molecular and genetic features. Understanding these differences is essential for clarifying tumor pathogenesis and improving diagnostic and therapeutic strategies. This review aims to compare these features and to better define the biological differences between testicular and ovarian GCTs. Methods: We reviewed cytogenetic alterations, epigenetic modifications, and somatic mutations reported in testicular and ovarian GCTs. Comparative analysis was performed to identify common and site-specific mechanisms. Results: Isochromosome 12p is a hallmark of testicular GCTs, while ovarian GCTs show diverse chromosomal changes. DNA methylation and other epigenetic marks differ by tumor subtype and gonadal origin. Somatic mutations affect pathways regulating cell cycle, pluripotency, and differentiation, with overlapping and unique patterns between testicular and ovarian tumors. Collectively, these findings define a molecular framework that explains both shared biology and gonadal-specific divergence in GCTs. Conclusions: Understanding molecular similarities and differences across gonadal GCTs can refine classification, guide biomarker discovery, and inform translational research. This comparative perspective highlights core pathogenetic mechanisms and gonadal-specific features relevant to clinical and experimental oncology.