[Pediatric germ cell tumors: An update 2025]

Area of Science:

• Pediatric Oncology
• Developmental Biology
• Cancer Genomics

Background:

• Pediatric germ cell tumors originate from primordial germ cells, exhibiting heterogeneity in origin and presentation.
• These rare cancers (3% of childhood cancers) occur in various gonadal and extragonadal sites across different age groups.
• Tumor distribution shows a bimodal pattern, with early childhood peaks of benign extragonadal tumors and prepubertal peaks of gonadal, cerebral, and mediastinal tumors.

Purpose of the Study:

• To summarize the understanding of pediatric germ cell tumors, including their etiology, epidemiology, and classification.
• To highlight the novel comprehensive approach in the 5th edition of the WHO tumor classification for pediatric germ cell tumors.
• To underscore the importance of histological type and tumor staging in determining prognosis and treatment.

Main Methods:

• Review of the 5th edition of the WHO tumor classification (2022) focusing on pediatric germ cell tumors.
• Analysis of epidemiological data regarding tumor distribution and age peaks.
• Integration of developmental, molecular biology, histological, and clinical management data.

Main Results:

• Pediatric germ cell tumors result from a combination of germ cell migration defects, genetic/epigenetic alterations, and a permissive microenvironment.
• Histological features are similar to adult tumors, but epidemiology and prognosis differ.
• The 2022 WHO classification adopts an organ-independent, comprehensive approach to these tumors.

Conclusions:

• Pediatric germ cell tumors are a diverse group with distinct epidemiological patterns and generally good prognoses.
• The new WHO classification provides an integrated framework for understanding and managing these tumors.
• Accurate pathological examination for histological typing and staging is crucial for effective treatment and improved patient outcomes.